251666406101 has 8 divisors (see below), whose sum is σ = 274554007104. Its totient is φ = 228780277920.

The previous prime is 251666406077. The next prime is 251666406119. The reversal of 251666406101 is 101604666152.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 251666406101 - 2²² = 251662211797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251666406151) 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, 5585 + ... + 709481.

It is an arithmetic number, because the mean of its divisors is an integer number (34319250888).

Almost surely, 2^251666406101 is an apocalyptic number.

It is an amenable number.

251666406101 is a deficient number, since it is larger than the sum of its proper divisors (22887601003).

251666406101 is a wasteful number, since it uses less digits than its factorization.

251666406101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 736411.

The product of its (nonzero) digits is 51840, while the sum is 38.

The spelling of 251666406101 in words is "two hundred fifty-one billion, six hundred sixty-six million, four hundred six thousand, one hundred one".