1581397532 has 96 divisors (see below), whose sum is σ = 3380106240. Its totient is φ = 637758720.

The previous prime is 1581397529. The next prime is 1581397537. The reversal of 1581397532 is 2357931851.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1581397537) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1585658 + ... + 1586654.

It is an arithmetic number, because the mean of its divisors is an integer number (35209440).

Almost surely, 2^1581397532 is an apocalyptic number.

It is an amenable number.

1581397532 is an abundant number, since it is smaller than the sum of its proper divisors (1798708708).

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

1581397532 is a wasteful number, since it uses less digits than its factorization.

1581397532 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1131 (or 1129 counting only the distinct ones).

The product of its digits is 226800, while the sum is 44.

The square root of 1581397532 is about 39766.7893096740. The cubic root of 1581397532 is about 1165.0565850195.

The spelling of 1581397532 in words is "one billion, five hundred eighty-one million, three hundred ninety-seven thousand, five hundred thirty-two".