861561250 has 40 divisors (see below), whose sum is σ = 1761748560. Its totient is φ = 313290000.

The previous prime is 861561229. The next prime is 861561271. The reversal of 861561250 is 52165168.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (861561229) and next prime (861561271).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 17580 + ... + 45079.

It is an arithmetic number, because the mean of its divisors is an integer number (44043714).

Almost surely, 2^861561250 is an apocalyptic number.

861561250 is an abundant number, since it is smaller than the sum of its proper divisors (900187310).

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

861561250 is a wasteful number, since it uses less digits than its factorization.

861561250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62692 (or 62677 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 34.

The square root of 861561250 is about 29352.3636186253. The cubic root of 861561250 is about 951.5436583971.

The spelling of 861561250 in words is "eight hundred sixty-one million, five hundred sixty-one thousand, two hundred fifty".