20639381465 has 8 divisors (see below), whose sum is σ = 26070797760. Its totient is φ = 15642478512.

The previous prime is 20639381431. The next prime is 20639381491. The reversal of 20639381465 is 56418393602.

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 20639381465 - 2²⁶ = 20572272601 is a prime.

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, 108628229 + ... + 108628418.

It is an arithmetic number, because the mean of its divisors is an integer number (3258849720).

Almost surely, 2^20639381465 is an apocalyptic number.

It is an amenable number.

20639381465 is a deficient number, since it is larger than the sum of its proper divisors (5431416295).

20639381465 is a wasteful number, since it uses less digits than its factorization.

20639381465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 217256671.

The product of its (nonzero) digits is 933120, while the sum is 47.

The spelling of 20639381465 in words is "twenty billion, six hundred thirty-nine million, three hundred eighty-one thousand, four hundred sixty-five".