661650771 has 8 divisors (see below), whose sum is σ = 882326464. Its totient is φ = 441037800.

The previous prime is 661650751. The next prime is 661650793. The reversal of 661650771 is 177056166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 661650771 - 2¹⁵ = 661618003 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661650751) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21600 + ... + 42306.

It is an arithmetic number, because the mean of its divisors is an integer number (110290808).

Almost surely, 2^661650771 is an apocalyptic number.

661650771 is a deficient number, since it is larger than the sum of its proper divisors (220675693).

661650771 is a wasteful number, since it uses less digits than its factorization.

661650771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31361.

The product of its (nonzero) digits is 52920, while the sum is 39.

The square root of 661650771 is about 25722.5731799911. The cubic root of 661650771 is about 871.3840527711.

The spelling of 661650771 in words is "six hundred sixty-one million, six hundred fifty thousand, seven hundred seventy-one".