21677031 has 16 divisors (see below), whose sum is σ = 32862720. Its totient is φ = 14114520.

The previous prime is 21677003. The next prime is 21677041. The reversal of 21677031 is 13077612.

It is not a de Polignac number, because 21677031 - 2⁵ = 21676999 is a prime.

It is a super-2 number, since 2×21677031² = 939787345949922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 21676986 and 21677004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21677041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8175 + ... + 10496.

It is an arithmetic number, because the mean of its divisors is an integer number (2053920).

Almost surely, 2^21677031 is an apocalyptic number.

21677031 is a deficient number, since it is larger than the sum of its proper divisors (11185689).

21677031 is a wasteful number, since it uses less digits than its factorization.

21677031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18723 (or 18717 counting only the distinct ones).

The product of its (nonzero) digits is 1764, while the sum is 27.

The square root of 21677031 is about 4655.8598561383. The cubic root of 21677031 is about 278.8259985690.

The spelling of 21677031 in words is "twenty-one million, six hundred seventy-seven thousand, thirty-one".