21145306465 has 8 divisors (see below), whose sum is σ = 25521041448. Its totient is φ = 16818462720.

The previous prime is 21145306447. The next prime is 21145306577. The reversal of 21145306465 is 56460354112.

It can be written as a sum of positive squares in 4 ways, for example, as 11161499904 + 9983806561 = 105648^2 + 99919^2 .

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

It is not a de Polignac number, because 21145306465 - 2⁹ = 21145305953 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12221856 + ... + 12223585.

It is an arithmetic number, because the mean of its divisors is an integer number (3190130181).

Almost surely, 2^21145306465 is an apocalyptic number.

It is an amenable number.

21145306465 is a deficient number, since it is larger than the sum of its proper divisors (4375734983).

21145306465 is a wasteful number, since it uses less digits than its factorization.

21145306465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24445619.

The product of its (nonzero) digits is 86400, while the sum is 37.

The spelling of 21145306465 in words is "twenty-one billion, one hundred forty-five million, three hundred six thousand, four hundred sixty-five".