861274540840 has 128 divisors (see below), whose sum is σ = 2219973350400. Its totient is φ = 294592757760.

The previous prime is 861274540781. The next prime is 861274540859. The reversal of 861274540840 is 48045472168.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 341638780 + ... + 341641300.

It is an arithmetic number, because the mean of its divisors is an integer number (17343541800).

Almost surely, 2^861274540840 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 861274540840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1109986675200).

861274540840 is an abundant number, since it is smaller than the sum of its proper divisors (1358698809560).

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

861274540840 is a wasteful number, since it uses less digits than its factorization.

861274540840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4955 (or 4951 counting only the distinct ones).

The product of its (nonzero) digits is 1720320, while the sum is 49.

The spelling of 861274540840 in words is "eight hundred sixty-one billion, two hundred seventy-four million, five hundred forty thousand, eight hundred forty".