66621774 has 16 divisors (see below), whose sum is σ = 134139600. Its totient is φ = 22057920.

The previous prime is 66621769. The next prime is 66621791. The reversal of 66621774 is 47712666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36367 + ... + 38154.

It is an arithmetic number, because the mean of its divisors is an integer number (8383725).

Almost surely, 2^66621774 is an apocalyptic number.

66621774 is an abundant number, since it is smaller than the sum of its proper divisors (67517826).

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

66621774 is a wasteful number, since it uses less digits than its factorization.

66621774 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74675.

The product of its digits is 84672, while the sum is 39.

The square root of 66621774 is about 8162.2162431536. The cubic root of 66621774 is about 405.3890971787.

The spelling of 66621774 in words is "sixty-six million, six hundred twenty-one thousand, seven hundred seventy-four".