71979660 has 36 divisors (see below), whose sum is σ = 218338848. Its totient is φ = 19194528.

The previous prime is 71979647. The next prime is 71979667. The reversal of 71979660 is 6697917.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (71979667) 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, 199764 + ... + 200123.

It is an arithmetic number, because the mean of its divisors is an integer number (6064968).

Almost surely, 2^71979660 is an apocalyptic number.

It is an amenable number.

71979660 is an abundant number, since it is smaller than the sum of its proper divisors (146359188).

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

71979660 is a wasteful number, since it uses less digits than its factorization.

71979660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 399902 (or 399897 counting only the distinct ones).

The product of its (nonzero) digits is 142884, while the sum is 45.

The square root of 71979660 is about 8484.0827435852. The cubic root of 71979660 is about 415.9775860088.

The spelling of 71979660 in words is "seventy-one million, nine hundred seventy-nine thousand, six hundred sixty".