861919461 has 40 divisors (see below), whose sum is σ = 1389683064. Its totient is φ = 529234560.

The previous prime is 861919459. The next prime is 861919483. The reversal of 861919461 is 164919168.

It can be written as a sum of positive squares in 4 ways, for example, as 66341025 + 795578436 = 8145^2 + 28206^2 .

It is not a de Polignac number, because 861919461 - 2¹ = 861919459 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861919451) by changing a digit.

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 39 ways as a sum of consecutive naturals, for example, 864015 + ... + 865011.

Almost surely, 2^861919461 is an apocalyptic number.

861919461 is a gapful number since it is divisible by the number (81) formed by its first and last digit.

It is an amenable number.

861919461 is a deficient number, since it is larger than the sum of its proper divisors (527763603).

861919461 is a wasteful number, since it uses less digits than its factorization.

861919461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1843 (or 1834 counting only the distinct ones).

The product of its digits is 93312, while the sum is 45.

The square root of 861919461 is about 29358.4648951542. The cubic root of 861919461 is about 951.6755144423.

The spelling of 861919461 in words is "eight hundred sixty-one million, nine hundred nineteen thousand, four hundred sixty-one".