21996687 has 8 divisors (see below), whose sum is σ = 29509504. Its totient is φ = 14574168.

The previous prime is 21996683. The next prime is 21996697. The reversal of 21996687 is 78669912.

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

It is not a de Polignac number, because 21996687 - 2² = 21996683 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21996683) 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, 22003 + ... + 22980.

It is an arithmetic number, because the mean of its divisors is an integer number (3688688).

Almost surely, 2^21996687 is an apocalyptic number.

21996687 is a deficient number, since it is larger than the sum of its proper divisors (7512817).

21996687 is a wasteful number, since it uses less digits than its factorization.

21996687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45149.

The product of its digits is 326592, while the sum is 48.

The square root of 21996687 is about 4690.0625795399. The cubic root of 21996687 is about 280.1898669711.

The spelling of 21996687 in words is "twenty-one million, nine hundred ninety-six thousand, six hundred eighty-seven".