1840125981 has 4 divisors (see below), whose sum is σ = 2453501312. Its totient is φ = 1226750652.

The previous prime is 1840125967. The next prime is 1840126007. The reversal of 1840125981 is 1895210481.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1895210481 = 3 ⋅631736827.

It is not a de Polignac number, because 1840125981 - 2⁵ = 1840125949 is a prime.

It is a super-2 number, since 2×1840125981² = 6772127251902424722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1840120981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 306687661 + ... + 306687666.

It is an arithmetic number, because the mean of its divisors is an integer number (613375328).

Almost surely, 2^1840125981 is an apocalyptic number.

It is an amenable number.

1840125981 is a deficient number, since it is larger than the sum of its proper divisors (613375331).

1840125981 is an equidigital number, since it uses as much as digits as its factorization.

1840125981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 613375330.

The product of its (nonzero) digits is 23040, while the sum is 39.

The square root of 1840125981 is about 42896.6896275225. The cubic root of 1840125981 is about 1225.4131009373.

The spelling of 1840125981 in words is "one billion, eight hundred forty million, one hundred twenty-five thousand, nine hundred eighty-one".