861431769 has 24 divisors (see below), whose sum is σ = 1437257952. Its totient is φ = 491368320.

The previous prime is 861431713. The next prime is 861431807. The reversal of 861431769 is 967134168.

It is a happy number.

It is not a de Polignac number, because 861431769 - 2¹⁷ = 861300697 is a prime.

It is a super-2 number, since 2×861431769² = 1484129385284938722, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (861430769) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 254239 + ... + 257604.

It is an arithmetic number, because the mean of its divisors is an integer number (59885748).

Almost surely, 2^861431769 is an apocalyptic number.

It is an amenable number.

861431769 is a deficient number, since it is larger than the sum of its proper divisors (575826183).

861431769 is a wasteful number, since it uses less digits than its factorization.

861431769 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 511877 (or 511874 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 861431769 is about 29350.1579041749. The cubic root of 861431769 is about 951.4959879627.

The spelling of 861431769 in words is "eight hundred sixty-one million, four hundred thirty-one thousand, seven hundred sixty-nine".