20418550278721 has 9 divisors (see below), whose sum is σ = 23752227935649. Its totient is φ = 17501587412484.

The previous prime is 20418550278691. The next prime is 20418550278787. The reversal of 20418550278721 is 12787205581402.

The square root of 20418550278721 is 4518689.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 20418550278721 - 2²³ = 20418541890113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20418550278421) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 31308060 + ... + 31953586.

Almost surely, 2^{20418550278721} is an apocalyptic number.

20418550278721 is the 4518689-th square number.

20418550278721 is the 2259345-th centered octagonal number.

It is an amenable number.

20418550278721 is a deficient number, since it is larger than the sum of its proper divisors (3333677656928).

20418550278721 is an frugal number, since it uses more digits than its factorization.

20418550278721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1291068 (or 645534 counting only the distinct ones).

The product of its (nonzero) digits is 2508800, while the sum is 52.

The spelling of 20418550278721 in words is "twenty trillion, four hundred eighteen billion, five hundred fifty million, two hundred seventy-eight thousand, seven hundred twenty-one".