861634620 has 432 divisors, whose sum is σ = 3388065408. Its totient is φ = 175230720.

The previous prime is 861634603. The next prime is 861634633. The reversal of 861634620 is 26436168.

861634620 is a `hidden beast` number, since 8 + 616 + 34 + 6 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 8052607 + ... + 8052713.

It is an arithmetic number, because the mean of its divisors is an integer number (7842744).

Almost surely, 2^861634620 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 861634620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1694032704).

861634620 is an abundant number, since it is smaller than the sum of its proper divisors (2526430788).

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

861634620 is a wasteful number, since it uses less digits than its factorization.

861634620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230 (or 218 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 861634620 is about 29353.6134061890. The cubic root of 861634620 is about 951.5706685783.

The spelling of 861634620 in words is "eight hundred sixty-one million, six hundred thirty-four thousand, six hundred twenty".