1561003380 has 96 divisors (see below), whose sum is σ = 4863022080. Its totient is φ = 415704960.

The previous prime is 1561003369. The next prime is 1561003391. The reversal of 1561003380 is 833001651.

1561003380 is a `hidden beast` number, since 15 + 610 + 0 + 3 + 38 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (1561003369) and next prime (1561003391).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 533682 + ... + 536598.

It is an arithmetic number, because the mean of its divisors is an integer number (50656480).

Almost surely, 2^1561003380 is an apocalyptic number.

1561003380 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 1561003380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2431511040).

1561003380 is an abundant number, since it is smaller than the sum of its proper divisors (3302018700).

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

1561003380 is a wasteful number, since it uses less digits than its factorization.

1561003380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3926 (or 3918 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 1561003380 is about 39509.5353047843. The cubic root of 1561003380 is about 1160.0265996675.

The spelling of 1561003380 in words is "one billion, five hundred sixty-one million, three thousand, three hundred eighty".