861211320 has 64 divisors (see below), whose sum is σ = 2614792320. Its totient is φ = 226886784.

The previous prime is 861211303. The next prime is 861211339. The reversal of 861211320 is 23112168.

It is a super-2 number, since 2×861211320² = 1483369875392284800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33274 + ... + 53193.

It is an arithmetic number, because the mean of its divisors is an integer number (40856130).

Almost surely, 2^861211320 is an apocalyptic number.

It is an amenable number.

861211320 is an abundant number, since it is smaller than the sum of its proper divisors (1753581000).

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

861211320 is a wasteful number, since it uses less digits than its factorization.

861211320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86564 (or 86560 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 861211320 is about 29346.4021644903. The cubic root of 861211320 is about 951.4148152601.

Adding to 861211320 its reverse (23112168), we get a palindrome (884323488).

The spelling of 861211320 in words is "eight hundred sixty-one million, two hundred eleven thousand, three hundred twenty".