78381921625 has 16 divisors (see below), whose sum is σ = 111795016320. Its totient is φ = 53747602800.

The previous prime is 78381921619. The next prime is 78381921647. The reversal of 78381921625 is 52612918387.

It is a happy number.

It is not a de Polignac number, because 78381921625 - 2⁹ = 78381921113 is a prime.

It is a super-2 number, since 2×78381921625² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 44788795 + ... + 44790544.

It is an arithmetic number, because the mean of its divisors is an integer number (6987188520).

Almost surely, 2^78381921625 is an apocalyptic number.

It is an amenable number.

78381921625 is a deficient number, since it is larger than the sum of its proper divisors (33413094695).

78381921625 is an equidigital number, since it uses as much as digits as its factorization.

78381921625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89579361 (or 89579351 counting only the distinct ones).

The product of its digits is 1451520, while the sum is 52.

The spelling of 78381921625 in words is "seventy-eight billion, three hundred eighty-one million, nine hundred twenty-one thousand, six hundred twenty-five".