21139115 has 16 divisors (see below), whose sum is σ = 27626400. Its totient is φ = 15466752.

The previous prime is 21139091. The next prime is 21139127. The reversal of 21139115 is 51193112.

It is a cyclic number.

It is not a de Polignac number, because 21139115 - 2¹⁶ = 21073579 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1082 + ... + 6591.

It is an arithmetic number, because the mean of its divisors is an integer number (1726650).

Almost surely, 2^21139115 is an apocalyptic number.

21139115 is a deficient number, since it is larger than the sum of its proper divisors (6487285).

21139115 is a wasteful number, since it uses less digits than its factorization.

21139115 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7726.

The product of its digits is 270, while the sum is 23.

The square root of 21139115 is about 4597.7293308763. The cubic root of 21139115 is about 276.5002959360.

The spelling of 21139115 in words is "twenty-one million, one hundred thirty-nine thousand, one hundred fifteen".