78362558621 has 2 divisors, whose sum is σ = 78362558622. Its totient is φ = 78362558620.

The previous prime is 78362558587. The next prime is 78362558671. The reversal of 78362558621 is 12685526387.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 52709731396 + 25652827225 = 229586^2 + 160165^2 .

It is a cyclic number.

It is not a de Polignac number, because 78362558621 - 2²² = 78358364317 is a prime.

It is a super-2 number, since 2×78362558621² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78362558671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39181279310 + 39181279311.

It is an arithmetic number, because the mean of its divisors is an integer number (39181279311).

Almost surely, 2^78362558621 is an apocalyptic number.

It is an amenable number.

78362558621 is a deficient number, since it is larger than the sum of its proper divisors (1).

78362558621 is an equidigital number, since it uses as much as digits as its factorization.

78362558621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4838400, while the sum is 53.

The spelling of 78362558621 in words is "seventy-eight billion, three hundred sixty-two million, five hundred fifty-eight thousand, six hundred twenty-one".