166781477404072 has 16 divisors (see below), whose sum is σ = 331110286023060. Its totient is φ = 78485401131264.

The previous prime is 166781477404067. The next prime is 166781477404109. The reversal of 166781477404072 is 270404774187661.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 164460772499076 + 2320704904996 = 12824226^2 + 1523386^2 .

It is a super-2 number, since 2×166781477404072² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 166781477403995 and 166781477404013.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 613167196203 + ... + 613167196474.

Almost surely, 2^{166781477404072} is an apocalyptic number.

It is an amenable number.

166781477404072 is a deficient number, since it is larger than the sum of its proper divisors (164328808618988).

166781477404072 is a wasteful number, since it uses less digits than its factorization.

166781477404072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1226334392700 (or 1226334392696 counting only the distinct ones).

The product of its (nonzero) digits is 88510464, while the sum is 64.

The spelling of 166781477404072 in words is "one hundred sixty-six trillion, seven hundred eighty-one billion, four hundred seventy-seven million, four hundred four thousand, seventy-two".