1661644706 has 8 divisors (see below), whose sum is σ = 2600835264. Its totient is φ = 794699620.

The previous prime is 1661644703. The next prime is 1661644727. The reversal of 1661644706 is 6074461661.

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

It is a super-2 number, since 2×1661644706² = 5522126257955652872, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1661644703) 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, 18061310 + ... + 18061401.

It is an arithmetic number, because the mean of its divisors is an integer number (325104408).

Almost surely, 2^1661644706 is an apocalyptic number.

1661644706 is a deficient number, since it is larger than the sum of its proper divisors (939190558).

1661644706 is a wasteful number, since it uses less digits than its factorization.

1661644706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36122736.

The product of its (nonzero) digits is 145152, while the sum is 41.

The square root of 1661644706 is about 40763.2764384808. The cubic root of 1661644706 is about 1184.4390648702.

The spelling of 1661644706 in words is "one billion, six hundred sixty-one million, six hundred forty-four thousand, seven hundred six".