1981890735 has 16 divisors (see below), whose sum is σ = 3459300480. Its totient is φ = 960916640.

The previous prime is 1981890731. The next prime is 1981890737. The reversal of 1981890735 is 5370981891.

It is not a de Polignac number, because 1981890735 - 2² = 1981890731 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981890731) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6005565 + ... + 6005894.

It is an arithmetic number, because the mean of its divisors is an integer number (216206280).

Almost surely, 2^1981890735 is an apocalyptic number.

1981890735 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1981890735 is a deficient number, since it is larger than the sum of its proper divisors (1477409745).

1981890735 is a wasteful number, since it uses less digits than its factorization.

1981890735 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12011478.

The product of its (nonzero) digits is 544320, while the sum is 51.

The square root of 1981890735 is about 44518.4314076765. The cubic root of 1981890735 is about 1256.1068070743.

The spelling of 1981890735 in words is "one billion, nine hundred eighty-one million, eight hundred ninety thousand, seven hundred thirty-five".