661369705 has 8 divisors (see below), whose sum is σ = 793787400. Its totient is φ = 528999936.

The previous prime is 661369703. The next prime is 661369739. The reversal of 661369705 is 507963166.

It can be written as a sum of positive squares in 4 ways, for example, as 33315984 + 628053721 = 5772^2 + 25061^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 661369705 - 2¹ = 661369703 is a prime.

It is not an unprimeable number, because it can be changed into a prime (661369703) 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, 35481 + ... + 50809.

It is an arithmetic number, because the mean of its divisors is an integer number (99223425).

Almost surely, 2^661369705 is an apocalyptic number.

It is an amenable number.

661369705 is a deficient number, since it is larger than the sum of its proper divisors (132417695).

661369705 is a wasteful number, since it uses less digits than its factorization.

661369705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23963.

The product of its (nonzero) digits is 204120, while the sum is 43.

The square root of 661369705 is about 25717.1091882428. The cubic root of 661369705 is about 871.2606487394.

The spelling of 661369705 in words is "six hundred sixty-one million, three hundred sixty-nine thousand, seven hundred five".