21377031 has 32 divisors (see below), whose sum is σ = 32598720. Its totient is φ = 12364800.

The previous prime is 21377029. The next prime is 21377039. The reversal of 21377031 is 13077312.

It is not a de Polignac number, because 21377031 - 2¹ = 21377029 is a prime.

It is a super-2 number, since 2×21377031² = 913954908749922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21376992 and 21377010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21377039) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 46141 + ... + 46601.

It is an arithmetic number, because the mean of its divisors is an integer number (1018710).

Almost surely, 2^21377031 is an apocalyptic number.

21377031 is a deficient number, since it is larger than the sum of its proper divisors (11221689).

21377031 is a wasteful number, since it uses less digits than its factorization.

21377031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 547.

The product of its (nonzero) digits is 882, while the sum is 24.

The square root of 21377031 is about 4623.5301448136. The cubic root of 21377031 is about 277.5337447804.

The spelling of 21377031 in words is "twenty-one million, three hundred seventy-seven thousand, thirty-one".