1561616064 has 112 divisors (see below), whose sum is σ = 4613696640. Its totient is φ = 517950720.

The previous prime is 1561616051. The next prime is 1561616081. The reversal of 1561616064 is 4606161651.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

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, 362467 + ... + 366749.

It is an arithmetic number, because the mean of its divisors is an integer number (41193720).

Almost surely, 2^1561616064 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1561616064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2306848320).

1561616064 is an abundant number, since it is smaller than the sum of its proper divisors (3052080576).

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

1561616064 is a wasteful number, since it uses less digits than its factorization.

1561616064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4515 (or 4499 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 1561616064 is about 39517.2881660673. The cubic root of 1561616064 is about 1160.1783475285.

The spelling of 1561616064 in words is "one billion, five hundred sixty-one million, six hundred sixteen thousand, sixty-four".