75720978 has 12 divisors (see below), whose sum is σ = 164062158. Its totient is φ = 25240320.

The previous prime is 75720977. The next prime is 75720989. The reversal of 75720978 is 87902757.

75720978 is a `hidden beast` number, since 7 + 572 + 0 + 9 + 78 = 666.

It can be written as a sum of positive squares in only one way, i.e., 68608089 + 7112889 = 8283^2 + 2667^2 .

It is not an unprimeable number, because it can be changed into a prime (75720977) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2103343 + ... + 2103378.

Almost surely, 2^75720978 is an apocalyptic number.

75720978 is an abundant number, since it is smaller than the sum of its proper divisors (88341180).

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

75720978 is a wasteful number, since it uses less digits than its factorization.

75720978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4206729 (or 4206726 counting only the distinct ones).

The product of its (nonzero) digits is 246960, while the sum is 45.

The square root of 75720978 is about 8701.7801627023. The cubic root of 75720978 is about 423.0633508390.

The spelling of 75720978 in words is "seventy-five million, seven hundred twenty thousand, nine hundred seventy-eight".