21425136 has 40 divisors (see below), whose sum is σ = 55651200. Its totient is φ = 7102656.

The previous prime is 21425099. The next prime is 21425147. The reversal of 21425136 is 63152412.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8431 + ... + 10673.

It is an arithmetic number, because the mean of its divisors is an integer number (1391280).

Almost surely, 2^21425136 is an apocalyptic number.

It is an amenable number.

21425136 is an abundant number, since it is smaller than the sum of its proper divisors (34226064).

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

21425136 is a wasteful number, since it uses less digits than its factorization.

21425136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2453 (or 2447 counting only the distinct ones).

The product of its digits is 1440, while the sum is 24.

The square root of 21425136 is about 4628.7294152931. The cubic root of 21425136 is about 277.7417680373.

Adding to 21425136 its reverse (63152412), we get a palindrome (84577548).

The spelling of 21425136 in words is "twenty-one million, four hundred twenty-five thousand, one hundred thirty-six".