861397740 has 240 divisors, whose sum is σ = 3173282112. Its totient is φ = 191476224.

The previous prime is 861397729. The next prime is 861397753. The reversal of 861397740 is 47793168.

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

It is a zygodrome in base 9.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 418554 + ... + 420606.

Almost surely, 2^861397740 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 861397740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1586641056).

861397740 is an abundant number, since it is smaller than the sum of its proper divisors (2311884372).

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

861397740 is a wasteful number, since it uses less digits than its factorization.

861397740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2118 (or 2107 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 45.

The square root of 861397740 is about 29349.5781911768. The cubic root of 861397740 is about 951.4834588670.

The spelling of 861397740 in words is "eight hundred sixty-one million, three hundred ninety-seven thousand, seven hundred forty".