21460040 has 48 divisors (see below), whose sum is σ = 56173500. Its totient is φ = 7357056.

The previous prime is 21460007. The next prime is 21460057. The reversal of 21460040 is 4006412.

21460040 = 645² + 646² + ... + 692².

It can be written as a sum of positive squares in 2 ways, for example, as 18957316 + 2502724 = 4354^2 + 1582^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3515 + ... + 7434.

Almost surely, 2^21460040 is an apocalyptic number.

21460040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21460040 is an abundant number, since it is smaller than the sum of its proper divisors (34713460).

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

21460040 is a wasteful number, since it uses less digits than its factorization.

21460040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10974 (or 10963 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 21460040 is about 4632.4982460871. The cubic root of 21460040 is about 277.8925105896.

Adding to 21460040 its reverse (4006412), we get a palindrome (25466452).

The spelling of 21460040 in words is "twenty-one million, four hundred sixty thousand, forty".