21915698 has 16 divisors (see below), whose sum is σ = 38782464. Its totient is φ = 9089280.

The previous prime is 21915697. The next prime is 21915701. The reversal of 21915698 is 89651912.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21915697) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24815 + ... + 25682.

It is an arithmetic number, because the mean of its divisors is an integer number (2423904).

Almost surely, 2^21915698 is an apocalyptic number.

21915698 is a deficient number, since it is larger than the sum of its proper divisors (16866766).

21915698 is a wasteful number, since it uses less digits than its factorization.

21915698 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50537.

The product of its digits is 38880, while the sum is 41.

The square root of 21915698 is about 4681.4205109133. The cubic root of 21915698 is about 279.8455696035.

The spelling of 21915698 in words is "twenty-one million, nine hundred fifteen thousand, six hundred ninety-eight".