66981772 has 24 divisors (see below), whose sum is σ = 137711952. Its totient is φ = 28104000.

The previous prime is 66981769. The next prime is 66981779. The reversal of 66981772 is 27718966.

It is a happy number.

It is a zygodrome in base 2.

It is not an unprimeable number, because it can be changed into a prime (66981779) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57979 + ... + 59122.

It is an arithmetic number, because the mean of its divisors is an integer number (5737998).

Almost surely, 2^66981772 is an apocalyptic number.

It is an amenable number.

66981772 is an abundant number, since it is smaller than the sum of its proper divisors (70730180).

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

66981772 is a wasteful number, since it uses less digits than its factorization.

66981772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117129 (or 117127 counting only the distinct ones).

The product of its digits is 254016, while the sum is 46.

The square root of 66981772 is about 8184.2392438149. The cubic root of 66981772 is about 406.1179739184.

The spelling of 66981772 in words is "sixty-six million, nine hundred eighty-one thousand, seven hundred seventy-two".