21996761 has 8 divisors (see below), whose sum is σ = 22809600. Its totient is φ = 21187600.

The previous prime is 21996757. The next prime is 21996797. The reversal of 21996761 is 16769912.

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 21996761 - 2² = 21996757 is a prime.

It is a super-2 number, since 2×21996761² = 967714988982242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21996731) 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, 18536 + ... + 19686.

It is an arithmetic number, because the mean of its divisors is an integer number (2851200).

Almost surely, 2^21996761 is an apocalyptic number.

It is an amenable number.

21996761 is a deficient number, since it is larger than the sum of its proper divisors (812839).

21996761 is a wasteful number, since it uses less digits than its factorization.

21996761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1839.

The product of its digits is 40824, while the sum is 41.

The square root of 21996761 is about 4690.0704685538. The cubic root of 21996761 is about 280.1901811703.

The spelling of 21996761 in words is "twenty-one million, nine hundred ninety-six thousand, seven hundred sixty-one".