21711977 has 8 divisors (see below), whose sum is σ = 25892736. Its totient is φ = 17800992.

The previous prime is 21711973. The next prime is 21712057. The reversal of 21711977 is 77911712.

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 21711977 - 2² = 21711973 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21711973) 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, 67268 + ... + 67589.

It is an arithmetic number, because the mean of its divisors is an integer number (3236592).

Almost surely, 2^21711977 is an apocalyptic number.

It is an amenable number.

21711977 is a deficient number, since it is larger than the sum of its proper divisors (4180759).

21711977 is a wasteful number, since it uses less digits than its factorization.

21711977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134887.

The product of its digits is 6174, while the sum is 35.

The square root of 21711977 is about 4659.6112498791. The cubic root of 21711977 is about 278.9757518869.

The spelling of 21711977 in words is "twenty-one million, seven hundred eleven thousand, nine hundred seventy-seven".