251515462242 has 64 divisors (see below), whose sum is σ = 555861035520. Its totient is φ = 75232310400.

The previous prime is 251515462193. The next prime is 251515462249. The reversal of 251515462242 is 242264515152.

It is a self number, because there is not a number n which added to its sum of digits gives 251515462242.

It is not an unprimeable number, because it can be changed into a prime (251515462249) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6395134 + ... + 6434342.

It is an arithmetic number, because the mean of its divisors is an integer number (8685328680).

Almost surely, 2^251515462242 is an apocalyptic number.

251515462242 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 251515462242, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (277930517760).

251515462242 is an abundant number, since it is smaller than the sum of its proper divisors (304345573278).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

251515462242 is a wasteful number, since it uses less digits than its factorization.

251515462242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40479.

The product of its digits is 192000, while the sum is 39.

Adding to 251515462242 its reverse (242264515152), we get a palindrome (493779977394).

The spelling of 251515462242 in words is "two hundred fifty-one billion, five hundred fifteen million, four hundred sixty-two thousand, two hundred forty-two".