251345550503 has 4 divisors (see below), whose sum is σ = 251475715848. Its totient is φ = 251215385160.

The previous prime is 251345550493. The next prime is 251345550601. The reversal of 251345550503 is 305055543152.

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

It is a cyclic number.

It is not a de Polignac number, because 251345550503 - 2¹⁶ = 251345484967 is a prime.

It is a super-2 number, since 2×251345550503² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251345559503) 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, 65079776 + ... + 65083637.

It is an arithmetic number, because the mean of its divisors is an integer number (62868928962).

Almost surely, 2^251345550503 is an apocalyptic number.

251345550503 is a deficient number, since it is larger than the sum of its proper divisors (130165345).

251345550503 is a wasteful number, since it uses less digits than its factorization.

251345550503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130165344.

The product of its (nonzero) digits is 225000, while the sum is 38.

The spelling of 251345550503 in words is "two hundred fifty-one billion, three hundred forty-five million, five hundred fifty thousand, five hundred three".