861025620 has 192 divisors, whose sum is σ = 3063545856. Its totient is φ = 175772160.

The previous prime is 861025619. The next prime is 861025657. The reversal of 861025620 is 26520168.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 166717 + ... + 171803.

It is an arithmetic number, because the mean of its divisors is an integer number (15955968).

Almost surely, 2^861025620 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 861025620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1531772928).

861025620 is an abundant number, since it is smaller than the sum of its proper divisors (2202520236).

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

861025620 is a wasteful number, since it uses less digits than its factorization.

861025620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5150 (or 5148 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 30.

The square root of 861025620 is about 29343.2380626270. The cubic root of 861025620 is about 951.3464269225.

Adding to 861025620 its reverse (26520168), we get a palindrome (887545788).

The spelling of 861025620 in words is "eight hundred sixty-one million, twenty-five thousand, six hundred twenty".