78409975 has 12 divisors (see below), whose sum is σ = 111118384. Its totient is φ = 53766720.

The previous prime is 78409973. The next prime is 78410021. The reversal of 78409975 is 57990487.

It is a happy number.

It is not a de Polignac number, because 78409975 - 2¹ = 78409973 is a prime.

It is a super-2 number, since 2×78409975² = 12296248359001250, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78409973) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 223854 + ... + 224203.

Almost surely, 2^78409975 is an apocalyptic number.

78409975 is a deficient number, since it is larger than the sum of its proper divisors (32708409).

78409975 is a wasteful number, since it uses less digits than its factorization.

78409975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 448074 (or 448069 counting only the distinct ones).

The product of its (nonzero) digits is 635040, while the sum is 49.

The square root of 78409975 is about 8854.9407112640. The cubic root of 78409975 is about 428.0131430296.

The spelling of 78409975 in words is "seventy-eight million, four hundred nine thousand, nine hundred seventy-five".