78172459 has 4 divisors (see below), whose sum is σ = 78197416. Its totient is φ = 78147504.

The previous prime is 78172439. The next prime is 78172489. The reversal of 78172459 is 95427187.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78172459 is a prime.

It is a super-2 number, since 2×78172459² = 12221866692213362, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78172439) 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, 6969 + ... + 14314.

It is an arithmetic number, because the mean of its divisors is an integer number (19549354).

Almost surely, 2^78172459 is an apocalyptic number.

78172459 is a deficient number, since it is larger than the sum of its proper divisors (24957).

78172459 is a wasteful number, since it uses less digits than its factorization.

78172459 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24956.

The product of its digits is 141120, while the sum is 43.

The square root of 78172459 is about 8841.5190436938. The cubic root of 78172459 is about 427.5805331449.

The spelling of 78172459 in words is "seventy-eight million, one hundred seventy-two thousand, four hundred fifty-nine".