1661325536 has 24 divisors (see below), whose sum is σ = 3522330504. Its totient is φ = 766765440.

The previous prime is 1661325509. The next prime is 1661325539. The reversal of 1661325536 is 6355231661.

It is a self number, because there is not a number n which added to its sum of digits gives 1661325536.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661325539) 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, 1996370 + ... + 1997201.

It is an arithmetic number, because the mean of its divisors is an integer number (146763771).

Almost surely, 2^1661325536 is an apocalyptic number.

1661325536 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1661325536 is an abundant number, since it is smaller than the sum of its proper divisors (1861004968).

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

1661325536 is a wasteful number, since it uses less digits than its factorization.

1661325536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3993594 (or 3993586 counting only the distinct ones).

The product of its digits is 97200, while the sum is 38.

The square root of 1661325536 is about 40759.3613296381. The cubic root of 1661325536 is about 1184.3632240237.

The spelling of 1661325536 in words is "one billion, six hundred sixty-one million, three hundred twenty-five thousand, five hundred thirty-six".