78421863 has 16 divisors (see below), whose sum is σ = 112817376. Its totient is φ = 48168960.

The previous prime is 78421859. The next prime is 78421919. The reversal of 78421863 is 36812487.

It is not a de Polignac number, because 78421863 - 2² = 78421859 is a prime.

It is a super-2 number, since 2×78421863² = 12299977192781538, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78421813) 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, 23431 + ... + 26567.

It is an arithmetic number, because the mean of its divisors is an integer number (7051086).

Almost surely, 2^78421863 is an apocalyptic number.

78421863 is a deficient number, since it is larger than the sum of its proper divisors (34395513).

78421863 is a wasteful number, since it uses less digits than its factorization.

78421863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3794.

The product of its digits is 64512, while the sum is 39.

The square root of 78421863 is about 8855.6119494928. The cubic root of 78421863 is about 428.0347727738.

The spelling of 78421863 in words is "seventy-eight million, four hundred twenty-one thousand, eight hundred sixty-three".