251856117103 has 4 divisors (see below), whose sum is σ = 262806383088. Its totient is φ = 240905851120.

The previous prime is 251856117101. The next prime is 251856117119. The reversal of 251856117103 is 301711658152.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 251856117103 - 2¹ = 251856117101 is a prime.

It is a super-3 number, since 3×251856117103³ (a number of 35 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251856117101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5475132958 + ... + 5475133003.

It is an arithmetic number, because the mean of its divisors is an integer number (65701595772).

Almost surely, 2^251856117103 is an apocalyptic number.

251856117103 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

251856117103 is a deficient number, since it is larger than the sum of its proper divisors (10950265985).

251856117103 is a wasteful number, since it uses less digits than its factorization.

251856117103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10950265984.

The product of its (nonzero) digits is 50400, while the sum is 40.

The spelling of 251856117103 in words is "two hundred fifty-one billion, eight hundred fifty-six million, one hundred seventeen thousand, one hundred three".