21127707 has 6 divisors (see below), whose sum is σ = 30517812. Its totient is φ = 14085132.

The previous prime is 21127699. The next prime is 21127721. The reversal of 21127707 is 70772112.

It is not a de Polignac number, because 21127707 - 2³ = 21127699 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21127727) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1173753 + ... + 1173770.

It is an arithmetic number, because the mean of its divisors is an integer number (5086302).

Almost surely, 2^21127707 is an apocalyptic number.

21127707 is a deficient number, since it is larger than the sum of its proper divisors (9390105).

21127707 is a wasteful number, since it uses less digits than its factorization.

21127707 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2347529 (or 2347526 counting only the distinct ones).

The product of its (nonzero) digits is 1372, while the sum is 27.

The square root of 21127707 is about 4596.4885510572. The cubic root of 21127707 is about 276.4505479851.

Adding to 21127707 its reverse (70772112), we get a palindrome (91899819).

The spelling of 21127707 in words is "twenty-one million, one hundred twenty-seven thousand, seven hundred seven".