78575622421 has 2 divisors, whose sum is σ = 78575622422. Its totient is φ = 78575622420.

The previous prime is 78575622299. The next prime is 78575622431. The reversal of 78575622421 is 12422657587.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69835990225 + 8739632196 = 264265^2 + 93486^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78575622421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78575622431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39287811210 + 39287811211.

It is an arithmetic number, because the mean of its divisors is an integer number (39287811211).

Almost surely, 2^78575622421 is an apocalyptic number.

It is an amenable number.

78575622421 is a deficient number, since it is larger than the sum of its proper divisors (1).

78575622421 is an equidigital number, since it uses as much as digits as its factorization.

78575622421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1881600, while the sum is 49.

The spelling of 78575622421 in words is "seventy-eight billion, five hundred seventy-five million, six hundred twenty-two thousand, four hundred twenty-one".