21090038 has 16 divisors (see below), whose sum is σ = 34077120. Its totient is φ = 9756936.

The previous prime is 21090007. The next prime is 21090061. The reversal of 21090038 is 83009012.

It is a junction number, because it is equal to n+sod(n) for n = 21089995 and 21090022.

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, 4820 + ... + 8087.

It is an arithmetic number, because the mean of its divisors is an integer number (2129820).

Almost surely, 2^21090038 is an apocalyptic number.

21090038 is a deficient number, since it is larger than the sum of its proper divisors (12987082).

21090038 is a wasteful number, since it uses less digits than its factorization.

21090038 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12971.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 21090038 is about 4592.3891385639. The cubic root of 21090038 is about 276.2861538918.

The spelling of 21090038 in words is "twenty-one million, ninety thousand, thirty-eight".