78764241025621 has 4 divisors (see below), whose sum is σ = 78764537699500. Its totient is φ = 78763944351744.

The previous prime is 78764241025607. The next prime is 78764241025637. The reversal of 78764241025621 is 12652014246787.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 41968552282596 + 36795688743025 = 6478314^2 + 6065945^2 .

It is a cyclic number.

It is not a de Polignac number, because 78764241025621 - 2³⁷ = 78626802072149 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 (78764241025601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 147938346 + ... + 148469803.

It is an arithmetic number, because the mean of its divisors is an integer number (19691134424875).

Almost surely, 2^{78764241025621} is an apocalyptic number.

It is an amenable number.

78764241025621 is a deficient number, since it is larger than the sum of its proper divisors (296673879).

78764241025621 is a wasteful number, since it uses less digits than its factorization.

78764241025621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 296673878.

The product of its (nonzero) digits is 9031680, while the sum is 55.

The spelling of 78764241025621 in words is "seventy-eight trillion, seven hundred sixty-four billion, two hundred forty-one million, twenty-five thousand, six hundred twenty-one".