21901867 has 16 divisors (see below), whose sum is σ = 24373440. Its totient is φ = 19555200.

The previous prime is 21901853. The next prime is 21901897. The reversal of 21901867 is 76810912.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21901867 - 2⁷ = 21901739 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21901837) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 56109 + ... + 56497.

It is an arithmetic number, because the mean of its divisors is an integer number (1523340).

Almost surely, 2^21901867 is an apocalyptic number.

21901867 is a deficient number, since it is larger than the sum of its proper divisors (2471573).

21901867 is a wasteful number, since it uses less digits than its factorization.

21901867 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 534.

The product of its (nonzero) digits is 6048, while the sum is 34.

The square root of 21901867 is about 4679.9430552091. The cubic root of 21901867 is about 279.7866870224.

The spelling of 21901867 in words is "twenty-one million, nine hundred one thousand, eight hundred sixty-seven".