21492560 has 80 divisors (see below), whose sum is σ = 52670736. Its totient is φ = 8146944.

The previous prime is 21492551. The next prime is 21492563. The reversal of 21492560 is 6529412.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 2062096 + 19430464 = 1436^2 + 4408^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21492563) 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 15 ways as a sum of consecutive naturals, for example, 156812 + ... + 156948.

Almost surely, 2^21492560 is an apocalyptic number.

21492560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21492560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26335368).

21492560 is an abundant number, since it is smaller than the sum of its proper divisors (31178176).

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

21492560 is a wasteful number, since it uses less digits than its factorization.

21492560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240 (or 234 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 21492560 is about 4636.0069024970. The cubic root of 21492560 is about 278.0328101641.

The spelling of 21492560 in words is "twenty-one million, four hundred ninety-two thousand, five hundred sixty".