861967872 has 160 divisors (see below), whose sum is σ = 2663400960. Its totient is φ = 274728960.

The previous prime is 861967871. The next prime is 861967913. The reversal of 861967872 is 278769168.

It is a super-2 number, since 2×861967872² = 1485977224720416768, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861967871) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 316597 + ... + 319307.

It is an arithmetic number, because the mean of its divisors is an integer number (16646256).

Almost surely, 2^861967872 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 861967872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1331700480).

861967872 is an abundant number, since it is smaller than the sum of its proper divisors (1801433088).

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

861967872 is a wasteful number, since it uses less digits than its factorization.

861967872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2761 (or 2739 counting only the distinct ones).

The product of its digits is 2032128, while the sum is 54.

The square root of 861967872 is about 29359.2893646968. The cubic root of 861967872 is about 951.6933315366.

The spelling of 861967872 in words is "eight hundred sixty-one million, nine hundred sixty-seven thousand, eight hundred seventy-two".