1561612416 has 512 divisors, whose sum is σ = 5593190400. Its totient is φ = 374685696.

The previous prime is 1561612391. The next prime is 1561612421. The reversal of 1561612416 is 6142161651.

Its product of digits (8640) is a multiple of the sum of its prime divisors (144).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 23307615 + ... + 23307681.

It is an arithmetic number, because the mean of its divisors is an integer number (10924200).

Almost surely, 2^1561612416 is an apocalyptic number.

1561612416 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1561612416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2796595200).

1561612416 is an abundant number, since it is smaller than the sum of its proper divisors (4031577984).

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

1561612416 is a wasteful number, since it uses less digits than its factorization.

1561612416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156 (or 144 counting only the distinct ones).

The product of its digits is 8640, while the sum is 33.

The square root of 1561612416 is about 39517.2420090269. The cubic root of 1561612416 is about 1160.1774441195.

It can be divided in two parts, 1561612 and 416, that added together give a triangular number (1562028 = T₁₇₆₇).

The spelling of 1561612416 in words is "one billion, five hundred sixty-one million, six hundred twelve thousand, four hundred sixteen".