78990451 has 4 divisors (see below), whose sum is σ = 79014832. Its totient is φ = 78966072.

The previous prime is 78990433. The next prime is 78990469. The reversal of 78990451 is 15409987.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (78990433) and next prime (78990469).

It is a cyclic number.

It is not a de Polignac number, because 78990451 - 2⁷ = 78990323 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78990398 and 78990407.

It is not an unprimeable number, because it can be changed into a prime (78990421) 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, 6420 + ... + 14113.

It is an arithmetic number, because the mean of its divisors is an integer number (19753708).

Almost surely, 2^78990451 is an apocalyptic number.

78990451 is a deficient number, since it is larger than the sum of its proper divisors (24381).

78990451 is a wasteful number, since it uses less digits than its factorization.

78990451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24380.

The product of its (nonzero) digits is 90720, while the sum is 43.

The square root of 78990451 is about 8887.6572278638. The cubic root of 78990451 is about 429.0667537211.

The spelling of 78990451 in words is "seventy-eight million, nine hundred ninety thousand, four hundred fifty-one".