21452536 has 16 divisors (see below), whose sum is σ = 45969840. Its totient is φ = 9193920.

The previous prime is 21452533. The next prime is 21452549. The reversal of 21452536 is 63525412.

It is a super-2 number, since 2×21452536² = 920422601662592, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21452533) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 191485 + ... + 191596.

It is an arithmetic number, because the mean of its divisors is an integer number (2873115).

Almost surely, 2^21452536 is an apocalyptic number.

It is an amenable number.

21452536 is an abundant number, since it is smaller than the sum of its proper divisors (24517304).

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

21452536 is a wasteful number, since it uses less digits than its factorization.

21452536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 383094 (or 383090 counting only the distinct ones).

The product of its digits is 7200, while the sum is 28.

The square root of 21452536 is about 4631.6882451219. The cubic root of 21452536 is about 277.8601162961.

Adding to 21452536 its reverse (63525412), we get a palindrome (84977948).

The spelling of 21452536 in words is "twenty-one million, four hundred fifty-two thousand, five hundred thirty-six".