661901382 has 56 divisors (see below), whose sum is σ = 1493859936. Its totient is φ = 219854736.

The previous prime is 661901369. The next prime is 661901411. The reversal of 661901382 is 283109166.

661901382 is a `hidden beast` number, since 6 + 619 + 0 + 1 + 38 + 2 = 666.

661901382 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×661901382² = 876226878987019848, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 534468 + ... + 535704.

Almost surely, 2^661901382 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661901382, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (746929968).

661901382 is an abundant number, since it is smaller than the sum of its proper divisors (831958554).

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

661901382 is a wasteful number, since it uses less digits than its factorization.

661901382 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1624 (or 1609 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 661901382 is about 25727.4441404505. Note that the first 3 decimals coincide. The cubic root of 661901382 is about 871.4940558486.

The spelling of 661901382 in words is "six hundred sixty-one million, nine hundred one thousand, three hundred eighty-two".