21528536 has 8 divisors (see below), whose sum is σ = 40366020. Its totient is φ = 10764264.

The previous prime is 21528517. The next prime is 21528553. The reversal of 21528536 is 63582512.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1345526 + ... + 1345541.

Almost surely, 2^21528536 is an apocalyptic number.

It is an amenable number.

21528536 is a deficient number, since it is larger than the sum of its proper divisors (18837484).

21528536 is a wasteful number, since it uses less digits than its factorization.

21528536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2691073 (or 2691069 counting only the distinct ones).

The product of its digits is 14400, while the sum is 32.

The square root of 21528536 is about 4639.8853434110. The cubic root of 21528536 is about 278.1878550192.

The spelling of 21528536 in words is "twenty-one million, five hundred twenty-eight thousand, five hundred thirty-six".