78416251421 has 4 divisors (see below), whose sum is σ = 78471204672. Its totient is φ = 78361298172.

The previous prime is 78416251391. The next prime is 78416251427. The reversal of 78416251421 is 12415261487.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 78416251421 - 2⁶ = 78416251357 is a prime.

It is a super-2 number, since 2×78416251421² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78416251427) 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, 27474485 + ... + 27477338.

It is an arithmetic number, because the mean of its divisors is an integer number (19617801168).

Almost surely, 2^78416251421 is an apocalyptic number.

It is an amenable number.

78416251421 is a deficient number, since it is larger than the sum of its proper divisors (54953251).

78416251421 is a wasteful number, since it uses less digits than its factorization.

78416251421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54953250.

The product of its digits is 107520, while the sum is 41.

The spelling of 78416251421 in words is "seventy-eight billion, four hundred sixteen million, two hundred fifty-one thousand, four hundred twenty-one".