25642201780 has 24 divisors (see below), whose sum is σ = 57990826152. Its totient is φ = 9467889792.

The previous prime is 25642201777. The next prime is 25642201799. The reversal of 25642201780 is 8710224652.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 640899856 + 25001301924 = 25316^2 + 158118^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49311667 + ... + 49312186.

It is an arithmetic number, because the mean of its divisors is an integer number (2416284423).

Almost surely, 2^25642201780 is an apocalyptic number.

25642201780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25642201780 is an abundant number, since it is smaller than the sum of its proper divisors (32348624372).

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

25642201780 is a wasteful number, since it uses less digits than its factorization.

25642201780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98623875 (or 98623873 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 37.

The spelling of 25642201780 in words is "twenty-five billion, six hundred forty-two million, two hundred one thousand, seven hundred eighty".