21386761 has 8 divisors (see below), whose sum is σ = 24559200. Its totient is φ = 18419040.

The previous prime is 21386759. The next prime is 21386773. The reversal of 21386761 is 16768312.

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 21386761 - 2¹ = 21386759 is a prime.

It is a super-2 number, since 2×21386761² = 914787092142242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21386791) 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, 50956 + ... + 51373.

It is an arithmetic number, because the mean of its divisors is an integer number (3069900).

Almost surely, 2^21386761 is an apocalyptic number.

It is an amenable number.

21386761 is a deficient number, since it is larger than the sum of its proper divisors (3172439).

21386761 is a wasteful number, since it uses less digits than its factorization.

21386761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102359.

The product of its digits is 12096, while the sum is 34.

The square root of 21386761 is about 4624.5822514039. The cubic root of 21386761 is about 277.5758459455.

The spelling of 21386761 in words is "twenty-one million, three hundred eighty-six thousand, seven hundred sixty-one".