861619646 has 4 divisors (see below), whose sum is σ = 1292429472. Its totient is φ = 430809822.

The previous prime is 861619639. The next prime is 861619679. The reversal of 861619646 is 646916168.

It is a semiprime because it is the product of two primes.

It is a self number, because there is not a number n which added to its sum of digits gives 861619646.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 215404910 + ... + 215404913.

It is an arithmetic number, because the mean of its divisors is an integer number (323107368).

Almost surely, 2^861619646 is an apocalyptic number.

861619646 is a deficient number, since it is larger than the sum of its proper divisors (430809826).

861619646 is a wasteful number, since it uses less digits than its factorization.

861619646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 430809825.

The product of its digits is 373248, while the sum is 47.

The square root of 861619646 is about 29353.3583427859. The cubic root of 861619646 is about 951.5651562256.

The spelling of 861619646 in words is "eight hundred sixty-one million, six hundred nineteen thousand, six hundred forty-six".