251631120206 has 8 divisors (see below), whose sum is σ = 377817092280. Its totient is φ = 125692089448.

The previous prime is 251631120193. The next prime is 251631120233. The reversal of 251631120206 is 602021136152.

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

It is a super-2 number, since 2×251631120206² (a number of 24 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61732781 + ... + 61736856.

It is an arithmetic number, because the mean of its divisors is an integer number (47227136535).

Almost surely, 2^251631120206 is an apocalyptic number.

251631120206 is a deficient number, since it is larger than the sum of its proper divisors (126185972074).

251631120206 is a wasteful number, since it uses less digits than its factorization.

251631120206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123470658.

The product of its (nonzero) digits is 4320, while the sum is 29.

Adding to 251631120206 its reverse (602021136152), we get a palindrome (853652256358).

The spelling of 251631120206 in words is "two hundred fifty-one billion, six hundred thirty-one million, one hundred twenty thousand, two hundred six".