21641552 has 10 divisors (see below), whose sum is σ = 41930538. Its totient is φ = 10820768.

The previous prime is 21641537. The next prime is 21641579. The reversal of 21641552 is 25514612.

It can be written as a sum of positive squares in only one way, i.e., 18627856 + 3013696 = 4316^2 + 1736^2 .

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, 676283 + ... + 676314.

Almost surely, 2^21641552 is an apocalyptic number.

It is an amenable number.

21641552 is a deficient number, since it is larger than the sum of its proper divisors (20288986).

21641552 is a wasteful number, since it uses less digits than its factorization.

21641552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1352605 (or 1352599 counting only the distinct ones).

The product of its digits is 2400, while the sum is 26.

The square root of 21641552 is about 4652.0481510836. The cubic root of 21641552 is about 278.6737964594.

The spelling of 21641552 in words is "twenty-one million, six hundred forty-one thousand, five hundred fifty-two".