1981523958 has 16 divisors (see below), whose sum is σ = 3972080640. Its totient is φ = 659002536.

The previous prime is 1981523923. The next prime is 1981523959. The reversal of 1981523958 is 8593251891.

It is a super-2 number, since 2×1981523958² = 7852874392255971528, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1981523958.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981523959) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 373510 + ... + 378777.

It is an arithmetic number, because the mean of its divisors is an integer number (248255040).

Almost surely, 2^1981523958 is an apocalyptic number.

1981523958 is an abundant number, since it is smaller than the sum of its proper divisors (1990556682).

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

1981523958 is a wasteful number, since it uses less digits than its factorization.

1981523958 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 752731.

The product of its digits is 777600, while the sum is 51.

The square root of 1981523958 is about 44514.3118333868. The cubic root of 1981523958 is about 1256.0293154983.

The spelling of 1981523958 in words is "one billion, nine hundred eighty-one million, five hundred twenty-three thousand, nine hundred fifty-eight".