21537048 has 32 divisors (see below), whose sum is σ = 57985200. Its totient is φ = 6626688.

The previous prime is 21537029. The next prime is 21537049. The reversal of 21537048 is 84073512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21537049) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34203 + ... + 34826.

Almost surely, 2^21537048 is an apocalyptic number.

It is an amenable number.

21537048 is an abundant number, since it is smaller than the sum of its proper divisors (36448152).

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

21537048 is a wasteful number, since it uses less digits than its factorization.

21537048 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69051 (or 69047 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 21537048 is about 4640.8025168068. The cubic root of 21537048 is about 278.2245136973.

Subtracting 21537048 from its reverse (84073512), we obtain a square (62536464 = 7908²).

The spelling of 21537048 in words is "twenty-one million, five hundred thirty-seven thousand, forty-eight".