75721878 has 80 divisors (see below), whose sum is σ = 181587120. Its totient is φ = 23514624.

The previous prime is 75721873. The next prime is 75721883. The reversal of 75721878 is 87812757.

75721878 is a `hidden beast` number, since 7 + 572 + 1 + 8 + 78 = 666.

It is an interprime number because it is at equal distance from previous prime (75721873) and next prime (75721883).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (75721873) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 224526 + ... + 224862.

It is an arithmetic number, because the mean of its divisors is an integer number (2269839).

Almost surely, 2^75721878 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 75721878, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90793560).

75721878 is an abundant number, since it is smaller than the sum of its proper divisors (105865242).

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

75721878 is a wasteful number, since it uses less digits than its factorization.

75721878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 443 (or 434 counting only the distinct ones).

The product of its digits is 219520, while the sum is 45.

The square root of 75721878 is about 8701.8318761052. The cubic root of 75721878 is about 423.0650269730.

The spelling of 75721878 in words is "seventy-five million, seven hundred twenty-one thousand, eight hundred seventy-eight".