2051274778021 has 32 divisors (see below), whose sum is σ = 2443125934080. Its totient is φ = 1686104582976.

The previous prime is 2051274777991. The next prime is 2051274778043. The reversal of 2051274778021 is 1208774721502.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2051274778021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2051274778081) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2490255 + ... + 3209971.

It is an arithmetic number, because the mean of its divisors is an integer number (76347685440).

Almost surely, 2^{2051274778021} is an apocalyptic number.

It is an amenable number.

2051274778021 is a deficient number, since it is larger than the sum of its proper divisors (391851156059).

2051274778021 is a wasteful number, since it uses less digits than its factorization.

2051274778021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 719953.

The product of its (nonzero) digits is 439040, while the sum is 46.

The spelling of 2051274778021 in words is "two trillion, fifty-one billion, two hundred seventy-four million, seven hundred seventy-eight thousand, twenty-one".