257661065610 has 240 divisors, whose sum is σ = 753304860000. Its totient is φ = 63163152000.

The previous prime is 257661065579. The next prime is 257661065633. The reversal of 257661065610 is 16560166752.

257661065610 is a `hidden beast` number, since 2 + 5 + 76 + 6 + 10 + 6 + 561 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 34355641 + ... + 34363139.

It is an arithmetic number, because the mean of its divisors is an integer number (3138770250).

Almost surely, 2^257661065610 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 257661065610, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (376652430000).

257661065610 is an abundant number, since it is smaller than the sum of its proper divisors (495643794390).

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

257661065610 is a wasteful number, since it uses less digits than its factorization.

257661065610 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7795 (or 7773 counting only the distinct ones).

The product of its (nonzero) digits is 453600, while the sum is 45.

The spelling of 257661065610 in words is "two hundred fifty-seven billion, six hundred sixty-one million, sixty-five thousand, six hundred ten".