1242405540 has 84 divisors (see below), whose sum is σ = 3911833884. Its totient is φ = 331304256.

The previous prime is 1242405533. The next prime is 1242405547. The reversal of 1242405540 is 455042421.

It is an interprime number because it is at equal distance from previous prime (1242405533) and next prime (1242405547).

It can be written as a sum of positive squares in 2 ways, for example, as 504631296 + 737774244 = 22464^2 + 27162^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (1242405547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 28027 + ... + 57186.

It is an arithmetic number, because the mean of its divisors is an integer number (46569451).

Almost surely, 2^1242405540 is an apocalyptic number.

1242405540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1242405540 is an abundant number, since it is smaller than the sum of its proper divisors (2669428344).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1242405540 is an equidigital number, since it uses as much as digits as its factorization.

1242405540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85240 (or 85223 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 27.

The square root of 1242405540 is about 35247.7735467079. The cubic root of 1242405540 is about 1075.0313428756.

Adding to 1242405540 its reverse (455042421), we get a palindrome (1697447961).

The spelling of 1242405540 in words is "one billion, two hundred forty-two million, four hundred five thousand, five hundred forty".