1561539612 has 48 divisors (see below), whose sum is σ = 3737210400. Its totient is φ = 507171840.

The previous prime is 1561539599. The next prime is 1561539631. The reversal of 1561539612 is 2169351651.

It is a happy number.

It is a super-2 number, since 2×1561539612² = 4876811919690221088, 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 15 ways as a sum of consecutive naturals, for example, 524464 + ... + 527432.

It is an arithmetic number, because the mean of its divisors is an integer number (77858550).

Almost surely, 2^1561539612 is an apocalyptic number.

1561539612 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1561539612 is an abundant number, since it is smaller than the sum of its proper divisors (2175670788).

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

1561539612 is a wasteful number, since it uses less digits than its factorization.

1561539612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4086 (or 4084 counting only the distinct ones).

The product of its digits is 48600, while the sum is 39.

The square root of 1561539612 is about 39516.3208307656. The cubic root of 1561539612 is about 1160.1594142784.

The spelling of 1561539612 in words is "one billion, five hundred sixty-one million, five hundred thirty-nine thousand, six hundred twelve".