78421363990 has 32 divisors (see below), whose sum is σ = 150119716320. Its totient is φ = 29411195904.

The previous prime is 78421363967. The next prime is 78421363997. The reversal of 78421363990 is 9936312487.

It is a super-2 number, since 2×78421363990² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78421363997) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2109117 + ... + 2145976.

It is an arithmetic number, because the mean of its divisors is an integer number (4691241135).

Almost surely, 2^78421363990 is an apocalyptic number.

78421363990 is a deficient number, since it is larger than the sum of its proper divisors (71698352330).

78421363990 is a wasteful number, since it uses less digits than its factorization.

78421363990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4255216.

The product of its (nonzero) digits is 1959552, while the sum is 52.

The spelling of 78421363990 in words is "seventy-eight billion, four hundred twenty-one million, three hundred sixty-three thousand, nine hundred ninety".