257440487981 has 8 divisors (see below), whose sum is σ = 261344925504. Its totient is φ = 253537875360.

The previous prime is 257440487957. The next prime is 257440488007. The reversal of 257440487981 is 189784044752.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 257440487981 - 2²² = 257436293677 is a prime.

It is a super-2 number, since 2×257440487981² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 257440487981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257440487881) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 170600 + ... + 737553.

It is an arithmetic number, because the mean of its divisors is an integer number (32668115688).

Almost surely, 2^257440487981 is an apocalyptic number.

It is an amenable number.

257440487981 is a deficient number, since it is larger than the sum of its proper divisors (3904437523).

257440487981 is an equidigital number, since it uses as much as digits as its factorization.

257440487981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 912451.

The product of its (nonzero) digits is 18063360, while the sum is 59.

The spelling of 257440487981 in words is "two hundred fifty-seven billion, four hundred forty million, four hundred eighty-seven thousand, nine hundred eighty-one".