21761307 has 6 divisors (see below), whose sum is σ = 31433012. Its totient is φ = 14507532.

The previous prime is 21761303. The next prime is 21761347. The reversal of 21761307 is 70316712.

It is not a de Polignac number, because 21761307 - 2² = 21761303 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21761303) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1208953 + ... + 1208970.

Almost surely, 2^21761307 is an apocalyptic number.

21761307 is a deficient number, since it is larger than the sum of its proper divisors (9671705).

21761307 is a wasteful number, since it uses less digits than its factorization.

21761307 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2417929 (or 2417926 counting only the distinct ones).

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

The square root of 21761307 is about 4664.9016066794. The cubic root of 21761307 is about 279.1868713774.

The spelling of 21761307 in words is "twenty-one million, seven hundred sixty-one thousand, three hundred seven".