21464661 has 8 divisors (see below), whose sum is σ = 30125920. Its totient is φ = 13556592.

The previous prime is 21464657. The next prime is 21464671. The reversal of 21464661 is 16646412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21464661 - 2² = 21464657 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21464671) 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, 188230 + ... + 188343.

It is an arithmetic number, because the mean of its divisors is an integer number (3765740).

Almost surely, 2^21464661 is an apocalyptic number.

It is an amenable number.

21464661 is a deficient number, since it is larger than the sum of its proper divisors (8661259).

21464661 is a wasteful number, since it uses less digits than its factorization.

21464661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376595.

The product of its digits is 6912, while the sum is 30.

The square root of 21464661 is about 4632.9969781989. The cubic root of 21464661 is about 277.9124553976.

The spelling of 21464661 in words is "twenty-one million, four hundred sixty-four thousand, six hundred sixty-one".