661693754 has 48 divisors (see below), whose sum is σ = 1106804088. Its totient is φ = 295593984.

The previous prime is 661693741. The next prime is 661693757. The reversal of 661693754 is 457396166.

661693754 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 12 ways, for example, as 67650625 + 594043129 = 8225^2 + 24373^2 .

It is a super-2 number, since 2×661693754² = 875677248165225032, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 661693699 and 661693708.

It is not an unprimeable number, because it can be changed into a prime (661693757) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2087204 + ... + 2087520.

Almost surely, 2^661693754 is an apocalyptic number.

661693754 is a deficient number, since it is larger than the sum of its proper divisors (445110334).

661693754 is a wasteful number, since it uses less digits than its factorization.

661693754 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 467 (or 438 counting only the distinct ones).

The product of its digits is 816480, while the sum is 47.

The square root of 661693754 is about 25723.4086777006. The cubic root of 661693754 is about 871.4029216827.

The spelling of 661693754 in words is "six hundred sixty-one million, six hundred ninety-three thousand, seven hundred fifty-four".