21901258 has 8 divisors (see below), whose sum is σ = 32877252. Its totient is φ = 10942176.

The previous prime is 21901247. The next prime is 21901259. The reversal of 21901258 is 85210912.

It can be written as a sum of positive squares in 2 ways, for example, as 16670889 + 5230369 = 4083^2 + 2287^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21901259) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 235 + ... + 6622.

Almost surely, 2^21901258 is an apocalyptic number.

21901258 is the 2502-nd centered heptagonal number.

21901258 is a deficient number, since it is larger than the sum of its proper divisors (10975994).

21901258 is a wasteful number, since it uses less digits than its factorization.

21901258 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8456.

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 21901258 is about 4679.8779898626. The cubic root of 21901258 is about 279.7840937629.

The spelling of 21901258 in words is "twenty-one million, nine hundred one thousand, two hundred fifty-eight".