661093272 has 128 divisors (see below), whose sum is σ = 2105280000. Its totient is φ = 188293248.

The previous prime is 661093271. The next prime is 661093273. The reversal of 661093272 is 272390166.

661093272 is a `hidden beast` number, since 6 + 610 + 9 + 32 + 7 + 2 = 666.

It is an interprime number because it is at equal distance from previous prime (661093271) and next prime (661093273).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661093271) 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, 769179 + ... + 770037.

It is an arithmetic number, because the mean of its divisors is an integer number (16447500).

Almost surely, 2^661093272 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661093272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1052640000).

661093272 is an abundant number, since it is smaller than the sum of its proper divisors (1444186728).

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

661093272 is a wasteful number, since it uses less digits than its factorization.

661093272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1390 (or 1380 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 36.

The square root of 661093272 is about 25711.7341305483. The cubic root of 661093272 is about 871.1392447519.

The spelling of 661093272 in words is "six hundred sixty-one million, ninety-three thousand, two hundred seventy-two".