78906421 has 8 divisors (see below), whose sum is σ = 87048000. Its totient is φ = 70926240.

The previous prime is 78906413. The next prime is 78906437. The reversal of 78906421 is 12460987.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 78906421 - 2³ = 78906413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78906461) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39321 + ... + 41278.

It is an arithmetic number, because the mean of its divisors is an integer number (10881000).

Almost surely, 2^78906421 is an apocalyptic number.

It is an amenable number.

78906421 is a deficient number, since it is larger than the sum of its proper divisors (8141579).

78906421 is a wasteful number, since it uses less digits than its factorization.

78906421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80699.

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 78906421 is about 8882.9286274291. The cubic root of 78906421 is about 428.9145527427.

The spelling of 78906421 in words is "seventy-eight million, nine hundred six thousand, four hundred twenty-one".