25021866640 has 40 divisors (see below), whose sum is σ = 58436759808. Its totient is φ = 9963857280.

The previous prime is 25021866629. The next prime is 25021866677. The reversal of 25021866640 is 4666812052.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 25021866593 and 25021866602.

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 7 ways as a sum of consecutive naturals, for example, 683446 + ... + 719125.

Almost surely, 2^25021866640 is an apocalyptic number.

25021866640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25021866640 is an abundant number, since it is smaller than the sum of its proper divisors (33414893168).

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

25021866640 is a wasteful number, since it uses less digits than its factorization.

25021866640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1402807 (or 1402801 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 40.

The spelling of 25021866640 in words is "twenty-five billion, twenty-one million, eight hundred sixty-six thousand, six hundred forty".