78405552 has 60 divisors (see below), whose sum is σ = 230983480. Its totient is φ = 24758784.

The previous prime is 78405527. The next prime is 78405599. The reversal of 78405552 is 25550487.

It is a happy number.

It is a super-2 number, since 2×78405552² = 12294861168849408, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11593 + ... + 17064.

Almost surely, 2^78405552 is an apocalyptic number.

78405552 is a gapful number since it is divisible by the number (72) formed by its first and last digit.

It is an amenable number.

78405552 is an abundant number, since it is smaller than the sum of its proper divisors (152577928).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

78405552 is a wasteful number, since it uses less digits than its factorization.

78405552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28690 (or 28681 counting only the distinct ones).

The product of its (nonzero) digits is 56000, while the sum is 36.

The square root of 78405552 is about 8854.6909601634. The cubic root of 78405552 is about 428.0050949986.

The spelling of 78405552 in words is "seventy-eight million, four hundred five thousand, five hundred fifty-two".