21956977 has 8 divisors (see below), whose sum is σ = 25123392. Its totient is φ = 18798000.

The previous prime is 21956971. The next prime is 21956981. The reversal of 21956977 is 77965912.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21956977 - 2¹¹ = 21954929 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21956971) 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, 7902 + ... + 10312.

It is an arithmetic number, because the mean of its divisors is an integer number (3140424).

Almost surely, 2^21956977 is an apocalyptic number.

It is an amenable number.

21956977 is a deficient number, since it is larger than the sum of its proper divisors (3166415).

21956977 is a wasteful number, since it uses less digits than its factorization.

21956977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3719.

The product of its digits is 238140, while the sum is 46.

The square root of 21956977 is about 4685.8272482028. The cubic root of 21956977 is about 280.0211591153.

The spelling of 21956977 in words is "twenty-one million, nine hundred fifty-six thousand, nine hundred seventy-seven".