21113997 has 8 divisors (see below), whose sum is σ = 29633760. Its totient is φ = 13335120.

The previous prime is 21113993. The next prime is 21113999. The reversal of 21113997 is 79931112.

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

It is not a de Polignac number, because 21113997 - 2² = 21113993 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21113993) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 185154 + ... + 185267.

It is an arithmetic number, because the mean of its divisors is an integer number (3704220).

Almost surely, 2^21113997 is an apocalyptic number.

It is an amenable number.

21113997 is a deficient number, since it is larger than the sum of its proper divisors (8519763).

21113997 is a wasteful number, since it uses less digits than its factorization.

21113997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 370443.

The product of its digits is 3402, while the sum is 33.

The square root of 21113997 is about 4594.9969532090. The cubic root of 21113997 is about 276.3907377853.

The spelling of 21113997 in words is "twenty-one million, one hundred thirteen thousand, nine hundred ninety-seven".