1881521257825 has 24 divisors (see below), whose sum is σ = 2553316818336. Its totient is φ = 1364007216000.

The previous prime is 1881521257753. The next prime is 1881521257841. The reversal of 1881521257825 is 5287521251881.

It is a happy number.

It is not a de Polignac number, because 1881521257825 - 2¹¹ = 1881521255777 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (55).

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10843471 + ... + 11015620.

It is an arithmetic number, because the mean of its divisors is an integer number (106388200764).

Almost surely, 2^{1881521257825} is an apocalyptic number.

It is an amenable number.

1881521257825 is a deficient number, since it is larger than the sum of its proper divisors (671795560511).

1881521257825 is a wasteful number, since it uses less digits than its factorization.

1881521257825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21859425 (or 21859420 counting only the distinct ones).

The product of its digits is 3584000, while the sum is 55.

It can be divided in two parts, 1881521 and 257825, that added together give a triangular number (2139346 = T₂₀₆₈).

The spelling of 1881521257825 in words is "one trillion, eight hundred eighty-one billion, five hundred twenty-one million, two hundred fifty-seven thousand, eight hundred twenty-five".