66791772 has 18 divisors (see below), whose sum is σ = 168834848. Its totient is φ = 22263912.

The previous prime is 66791749. The next prime is 66791773. The reversal of 66791772 is 27719766.

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×66791772² = 8922281613799968, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66791773) 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, 927628 + ... + 927699.

Almost surely, 2^66791772 is an apocalyptic number.

It is an amenable number.

66791772 is an abundant number, since it is smaller than the sum of its proper divisors (102043076).

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

66791772 is a wasteful number, since it uses less digits than its factorization.

66791772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1855337 (or 1855332 counting only the distinct ones).

The product of its digits is 222264, while the sum is 45.

The square root of 66791772 is about 8172.6233242454. The cubic root of 66791772 is about 405.7336131817.

The spelling of 66791772 in words is "sixty-six million, seven hundred ninety-one thousand, seven hundred seventy-two".