661376733 has 4 divisors (see below), whose sum is σ = 881835648. Its totient is φ = 440917820.

The previous prime is 661376731. The next prime is 661376741. The reversal of 661376733 is 337673166.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 661376733 - 2¹ = 661376731 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661376731) 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, 110229453 + ... + 110229458.

It is an arithmetic number, because the mean of its divisors is an integer number (220458912).

Almost surely, 2^661376733 is an apocalyptic number.

It is an amenable number.

661376733 is a deficient number, since it is larger than the sum of its proper divisors (220458915).

661376733 is a wasteful number, since it uses less digits than its factorization.

661376733 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220458914.

The product of its digits is 285768, while the sum is 42.

The square root of 661376733 is about 25717.2458284319. The cubic root of 661376733 is about 871.2637348591.

The spelling of 661376733 in words is "six hundred sixty-one million, three hundred seventy-six thousand, seven hundred thirty-three".