21460691 has 4 divisors (see below), whose sum is σ = 24526512. Its totient is φ = 18394872.

The previous prime is 21460657. The next prime is 21460697. The reversal of 21460691 is 19606412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21460691 is a prime.

It is a super-2 number, since 2×21460691² = 921122516394962, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21460697) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1532900 + ... + 1532913.

It is an arithmetic number, because the mean of its divisors is an integer number (6131628).

Almost surely, 2^21460691 is an apocalyptic number.

21460691 is a deficient number, since it is larger than the sum of its proper divisors (3065821).

21460691 is an equidigital number, since it uses as much as digits as its factorization.

21460691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3065820.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 21460691 is about 4632.5685100169. The cubic root of 21460691 is about 277.8953205595.

The spelling of 21460691 in words is "twenty-one million, four hundred sixty thousand, six hundred ninety-one".