25251387640 has 16 divisors (see below), whose sum is σ = 56815622280. Its totient is φ = 10100555040.

The previous prime is 25251387617. The next prime is 25251387659. The reversal of 25251387640 is 4678315252.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 315642306 + ... + 315642385.

Almost surely, 2^25251387640 is an apocalyptic number.

25251387640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25251387640 is an abundant number, since it is smaller than the sum of its proper divisors (31564234640).

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

25251387640 is a wasteful number, since it uses less digits than its factorization.

25251387640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 631284702 (or 631284698 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 43.

The spelling of 25251387640 in words is "twenty-five billion, two hundred fifty-one million, three hundred eighty-seven thousand, six hundred forty".