21931038 has 12 divisors (see below), whose sum is σ = 47517288. Its totient is φ = 7310340.

The previous prime is 21931033. The next prime is 21931057. The reversal of 21931038 is 83013912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21931031) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 609178 + ... + 609213.

It is an arithmetic number, because the mean of its divisors is an integer number (3959774).

Almost surely, 2^21931038 is an apocalyptic number.

21931038 is an abundant number, since it is smaller than the sum of its proper divisors (25586250).

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

21931038 is a wasteful number, since it uses less digits than its factorization.

21931038 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1218399 (or 1218396 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 21931038 is about 4683.0586159048. The cubic root of 21931038 is about 279.9108474670.

The spelling of 21931038 in words is "twenty-one million, nine hundred thirty-one thousand, thirty-eight".