661273152 has 112 divisors (see below), whose sum is σ = 1817485824. Its totient is φ = 211968000.

The previous prime is 661273147. The next prime is 661273177. The reversal of 661273152 is 251372166.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1434202 + ... + 1434662.

It is an arithmetic number, because the mean of its divisors is an integer number (16227552).

Almost surely, 2^661273152 is an apocalyptic number.

661273152 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661273152, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (908742912).

661273152 is an abundant number, since it is smaller than the sum of its proper divisors (1156212672).

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

661273152 is a wasteful number, since it uses less digits than its factorization.

661273152 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 748 (or 738 counting only the distinct ones).

The product of its digits is 15120, while the sum is 33.

The square root of 661273152 is about 25715.2319064013. The cubic root of 661273152 is about 871.2182483881.

The spelling of 661273152 in words is "six hundred sixty-one million, two hundred seventy-three thousand, one hundred fifty-two".