251430442000 has 80 divisors (see below), whose sum is σ = 643721178672. Its totient is φ = 94656153600.

The previous prime is 251430441979. The next prime is 251430442007. The reversal of 251430442000 is 244034152.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 7615703824 + 243814738176 = 87268^2 + 493776^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (25).

It is not an unprimeable number, because it can be changed into a prime (251430442007) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3663507 + ... + 3731506.

Almost surely, 2^251430442000 is an apocalyptic number.

251430442000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

251430442000 is an abundant number, since it is smaller than the sum of its proper divisors (392290736672).

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

251430442000 is a wasteful number, since it uses less digits than its factorization.

251430442000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7395053 (or 7395037 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 25.

Adding to 251430442000 its reverse (244034152), we get a palindrome (251674476152).

The spelling of 251430442000 in words is "two hundred fifty-one billion, four hundred thirty million, four hundred forty-two thousand".