1981291560 has 64 divisors (see below), whose sum is σ = 6019142400. Its totient is φ = 521654016.

The previous prime is 1981291549. The next prime is 1981291573. The reversal of 1981291560 is 651921891.

It is a super-3 number, since 3×1981291560³ (a number of 29 digits) contains 333 as substring.

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, 95019 + ... + 113978.

It is an arithmetic number, because the mean of its divisors is an integer number (94049100).

Almost surely, 2^1981291560 is an apocalyptic number.

1981291560 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1981291560 is an abundant number, since it is smaller than the sum of its proper divisors (4037850840).

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

1981291560 is a wasteful number, since it uses less digits than its factorization.

1981291560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209090 (or 209086 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 42.

The square root of 1981291560 is about 44511.7013828948. The cubic root of 1981291560 is about 1255.9802101768.

The spelling of 1981291560 in words is "one billion, nine hundred eighty-one million, two hundred ninety-one thousand, five hundred sixty".