66654994391001 has 15 divisors (see below), whose sum is σ = 99571150767781. Its totient is φ = 44436613941828.

The previous prime is 66654994390903. The next prime is 66654994391003. The reversal of 66654994391001 is 10019349945666.

The square root of 66654994391001 is 8164251.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 66654994391001 - 2¹¹ = 66654994388953 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66654994391001.

It is not an unprimeable number, because it can be changed into a prime (66654994391003) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 73024690 + ... + 73931828.

Almost surely, 2^{66654994391001} is an apocalyptic number.

66654994391001 is the 8164251-st square number.

66654994391001 is the 4082126-th centered octagonal number.

It is an amenable number.

66654994391001 is a deficient number, since it is larger than the sum of its proper divisors (32916156376780).

66654994391001 is an frugal number, since it uses more digits than its factorization.

66654994391001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1814290 (or 907142 counting only the distinct ones).

The product of its (nonzero) digits is 37791360, while the sum is 63.

The spelling of 66654994391001 in words is "sixty-six trillion, six hundred fifty-four billion, nine hundred ninety-four million, three hundred ninety-one thousand, one".