1561139996 has 24 divisors (see below), whose sum is σ = 3070070304. Its totient is φ = 689198400.

The previous prime is 1561139989. The next prime is 1561140041. The reversal of 1561139996 is 6999311651.

It is a super-2 number, since 2×1561139996² = 4874316174221760032, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 651455 + ... + 653846.

It is an arithmetic number, because the mean of its divisors is an integer number (127919596).

Almost surely, 2^1561139996 is an apocalyptic number.

It is an amenable number.

1561139996 is a deficient number, since it is larger than the sum of its proper divisors (1508930308).

1561139996 is a wasteful number, since it uses less digits than its factorization.

1561139996 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1305341 (or 1305339 counting only the distinct ones).

The product of its digits is 393660, while the sum is 50.

The square root of 1561139996 is about 39511.2641660578. The cubic root of 1561139996 is about 1160.0604397759.

The spelling of 1561139996 in words is "one billion, five hundred sixty-one million, one hundred thirty-nine thousand, nine hundred ninety-six".