661662705 has 32 divisors (see below), whose sum is σ = 1166836608. Its totient is φ = 317491200.

The previous prime is 661662647. The next prime is 661662713. The reversal of 661662705 is 507266166.

It is not a de Polignac number, because 661662705 - 2¹² = 661658609 is a prime.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4666 + ... + 36675.

It is an arithmetic number, because the mean of its divisors is an integer number (36463644).

Almost surely, 2^661662705 is an apocalyptic number.

It is an amenable number.

661662705 is a deficient number, since it is larger than the sum of its proper divisors (505173903).

661662705 is a wasteful number, since it uses less digits than its factorization.

661662705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41457.

The product of its (nonzero) digits is 90720, while the sum is 39.

The square root of 661662705 is about 25722.8051541818. The cubic root of 661662705 is about 871.3892917054.

It can be divided in two parts, 661 and 662705, that added together give a palindrome (663366).

The spelling of 661662705 in words is "six hundred sixty-one million, six hundred sixty-two thousand, seven hundred five".