1531991958 has 96 divisors (see below), whose sum is σ = 3938264064. Its totient is φ = 394023168.

The previous prime is 1531991953. The next prime is 1531991969. The reversal of 1531991958 is 8591991351.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1531991958.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1531991953) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 108291 + ... + 121617.

It is an arithmetic number, because the mean of its divisors is an integer number (41023584).

Almost surely, 2^1531991958 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1531991958, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1969132032).

1531991958 is an abundant number, since it is smaller than the sum of its proper divisors (2406272106).

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

1531991958 is a wasteful number, since it uses less digits than its factorization.

1531991958 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13386 (or 13379 counting only the distinct ones).

The product of its digits is 437400, while the sum is 51.

The square root of 1531991958 is about 39140.6688496760. The cubic root of 1531991958 is about 1152.7952062248.

The spelling of 1531991958 in words is "one billion, five hundred thirty-one million, nine hundred ninety-one thousand, nine hundred fifty-eight".