21065554 has 16 divisors (see below), whose sum is σ = 33417216. Its totient is φ = 9943200.

The previous prime is 21065549. The next prime is 21065563. The reversal of 21065554 is 45556012.

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, 1602 + ... + 6685.

It is an arithmetic number, because the mean of its divisors is an integer number (2088576).

Almost surely, 2^21065554 is an apocalyptic number.

21065554 is a deficient number, since it is larger than the sum of its proper divisors (12351662).

21065554 is a wasteful number, since it uses less digits than its factorization.

21065554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8361.

The product of its (nonzero) digits is 6000, while the sum is 28.

The square root of 21065554 is about 4589.7226495726. The cubic root of 21065554 is about 276.1791964487.

The spelling of 21065554 in words is "twenty-one million, sixty-five thousand, five hundred fifty-four".