1981249023 has 12 divisors (see below), whose sum is σ = 2860502280. Its totient is φ = 1219229856.

The previous prime is 1981249007. The next prime is 1981249031. The reversal of 1981249023 is 3209421891.

It is not a de Polignac number, because 1981249023 - 2⁴ = 1981249007 is a prime.

It is a super-3 number, since 3×1981249023³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981249043) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1953388 + ... + 1954401.

It is an arithmetic number, because the mean of its divisors is an integer number (238375190).

Almost surely, 2^1981249023 is an apocalyptic number.

1981249023 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1981249023 is a deficient number, since it is larger than the sum of its proper divisors (879253257).

1981249023 is a wasteful number, since it uses less digits than its factorization.

1981249023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3907818 (or 3907805 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 1981249023 is about 44511.2235621534. The cubic root of 1981249023 is about 1255.9712217617.

The spelling of 1981249023 in words is "one billion, nine hundred eighty-one million, two hundred forty-nine thousand, twenty-three".