78307644421 has 4 divisors (see below), whose sum is σ = 78308608000. Its totient is φ = 78306680844.

The previous prime is 78307644413. The next prime is 78307644433. The reversal of 78307644421 is 12444670387.

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 78307644421 - 2³ = 78307644413 is a prime.

It is a super-2 number, since 2×78307644421² (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 (78307642421) 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, 347391 + ... + 526588.

It is an arithmetic number, because the mean of its divisors is an integer number (19577152000).

Almost surely, 2^78307644421 is an apocalyptic number.

It is an amenable number.

78307644421 is a deficient number, since it is larger than the sum of its proper divisors (963579).

78307644421 is an equidigital number, since it uses as much as digits as its factorization.

78307644421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 963578.

The product of its (nonzero) digits is 903168, while the sum is 46.

The spelling of 78307644421 in words is "seventy-eight billion, three hundred seven million, six hundred forty-four thousand, four hundred twenty-one".