1561653760 has 80 divisors (see below), whose sum is σ = 3759795072. Its totient is φ = 622080000.

The previous prime is 1561653739. The next prime is 1561653823. The reversal of 1561653760 is 673561651.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×1561653760² = 4877524932244275200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

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, 692635 + ... + 694885.

Almost surely, 2^1561653760 is an apocalyptic number.

1561653760 is a gapful number since it is divisible by the number (10) 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 1561653760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1879897536).

1561653760 is an abundant number, since it is smaller than the sum of its proper divisors (2198141312).

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

1561653760 is an equidigital number, since it uses as much as digits as its factorization.

1561653760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2545 (or 2529 counting only the distinct ones).

The product of its (nonzero) digits is 113400, while the sum is 40.

The square root of 1561653760 is about 39517.7651189943. The cubic root of 1561653760 is about 1160.1876826722.

The spelling of 1561653760 in words is "one billion, five hundred sixty-one million, six hundred fifty-three thousand, seven hundred sixty".