166091772 has 72 divisors (see below), whose sum is σ = 491823360. Its totient is φ = 43139040.

The previous prime is 166091767. The next prime is 166091777. The reversal of 166091772 is 277190661.

It is an interprime number because it is at equal distance from previous prime (166091767) and next prime (166091777).

It is a self number, because there is not a number n which added to its sum of digits gives 166091772.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166091777) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6372 + ... + 19307.

It is an arithmetic number, because the mean of its divisors is an integer number (6830880).

Almost surely, 2^166091772 is an apocalyptic number.

166091772 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

166091772 is an abundant number, since it is smaller than the sum of its proper divisors (325731588).

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

166091772 is a wasteful number, since it uses less digits than its factorization.

166091772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25711 (or 25702 counting only the distinct ones).

The product of its (nonzero) digits is 31752, while the sum is 39.

The square root of 166091772 is about 12887.6596789332. The cubic root of 166091772 is about 549.6877257635.

It can be divided in two parts, 16609 and 1772, that added together give a palindrome (18381).

The spelling of 166091772 in words is "one hundred sixty-six million, ninety-one thousand, seven hundred seventy-two".