20516040 has 48 divisors (see below), whose sum is σ = 66678300. Its totient is φ = 5470848.

The previous prime is 20516039. The next prime is 20516047. The reversal of 20516040 is 4061502.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20088324 + 427716 = 4482^2 + 654^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (20516047) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28135 + ... + 28854.

Almost surely, 2^20516040 is an apocalyptic number.

20516040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20516040 is an abundant number, since it is smaller than the sum of its proper divisors (46162260).

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

20516040 is a wasteful number, since it uses less digits than its factorization.

20516040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57006 (or 56999 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 20516040 is about 4529.4635443946. The cubic root of 20516040 is about 273.7565457871.

Adding to 20516040 its reverse (4061502), we get a palindrome (24577542).

The spelling of 20516040 in words is "twenty million, five hundred sixteen thousand, forty".