20802218457 has 16 divisors (see below), whose sum is σ = 29202272000. Its totient is φ = 13135464144.

The previous prime is 20802218447. The next prime is 20802218539. The reversal of 20802218457 is 75481220802.

It is not a de Polignac number, because 20802218457 - 2¹⁴ = 20802202073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20802218447) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 252294 + ... + 324432.

It is an arithmetic number, because the mean of its divisors is an integer number (1825142000).

Almost surely, 2^20802218457 is an apocalyptic number.

It is an amenable number.

20802218457 is a deficient number, since it is larger than the sum of its proper divisors (8400053543).

20802218457 is a wasteful number, since it uses less digits than its factorization.

20802218457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77220.

The product of its (nonzero) digits is 71680, while the sum is 39.

The spelling of 20802218457 in words is "twenty billion, eight hundred two million, two hundred eighteen thousand, four hundred fifty-seven".