21902115 has 16 divisors (see below), whose sum is σ = 35407008. Its totient is φ = 11559936.

The previous prime is 21902107. The next prime is 21902119. The reversal of 21902115 is 51120912.

It is not a de Polignac number, because 21902115 - 2³ = 21902107 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21902091 and 21902100.

It is not an unprimeable number, because it can be changed into a prime (21902119) 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, 6072 + ... + 8981.

It is an arithmetic number, because the mean of its divisors is an integer number (2212938).

Almost surely, 2^21902115 is an apocalyptic number.

21902115 is a deficient number, since it is larger than the sum of its proper divisors (13504893).

21902115 is a wasteful number, since it uses less digits than its factorization.

21902115 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15158.

The product of its (nonzero) digits is 180, while the sum is 21.

The square root of 21902115 is about 4679.9695511830. The cubic root of 21902115 is about 279.7877430486.

The spelling of 21902115 in words is "twenty-one million, nine hundred two thousand, one hundred fifteen".