20971778968842 has 64 divisors (see below), whose sum is σ = 45284935078656. Its totient is φ = 6436440714240.

The previous prime is 20971778968831. The next prime is 20971778968853. The reversal of 20971778968842 is 24886987717902.

It is an interprime number because it is at equal distance from previous prime (20971778968831) and next prime (20971778968853).

It is a Harshad number since it is a multiple of its sum of digits (78).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 148230928 + ... + 148372340.

It is an arithmetic number, because the mean of its divisors is an integer number (707577110604).

Almost surely, 2^{20971778968842} is an apocalyptic number.

20971778968842 is an abundant number, since it is smaller than the sum of its proper divisors (24313156109814).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20971778968842 is a wasteful number, since it uses less digits than its factorization.

20971778968842 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146255.

The product of its (nonzero) digits is 1365590016, while the sum is 78.

The spelling of 20971778968842 in words is "twenty trillion, nine hundred seventy-one billion, seven hundred seventy-eight million, nine hundred sixty-eight thousand, eight hundred forty-two".