21401465621 has 8 divisors (see below), whose sum is σ = 21434418720. Its totient is φ = 21368537872.

The previous prime is 21401465609. The next prime is 21401465627. The reversal of 21401465621 is 12656410412.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21401465621 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 (21401465627) 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, 2267450 + ... + 2276868.

It is an arithmetic number, because the mean of its divisors is an integer number (2679302340).

Almost surely, 2^21401465621 is an apocalyptic number.

It is an amenable number.

21401465621 is a deficient number, since it is larger than the sum of its proper divisors (32953099).

21401465621 is a wasteful number, since it uses less digits than its factorization.

21401465621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12675.

The product of its (nonzero) digits is 11520, while the sum is 32.

The spelling of 21401465621 in words is "twenty-one billion, four hundred one million, four hundred sixty-five thousand, six hundred twenty-one".