20730661 has 16 divisors (see below), whose sum is σ = 24772608. Its totient is φ = 16974000.

The previous prime is 20730623. The next prime is 20730719. The reversal of 20730661 is 16603702.

It is a cyclic number.

It is not a de Polignac number, because 20730661 - 2⁷ = 20730533 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20739661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17436 + ... + 18586.

It is an arithmetic number, because the mean of its divisors is an integer number (1548288).

Almost surely, 2^20730661 is an apocalyptic number.

It is an amenable number.

20730661 is a deficient number, since it is larger than the sum of its proper divisors (4041947).

20730661 is a wasteful number, since it uses less digits than its factorization.

20730661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1272.

The product of its (nonzero) digits is 1512, while the sum is 25.

The square root of 20730661 is about 4553.0935637213. The cubic root of 20730661 is about 274.7078373720.

The spelling of 20730661 in words is "twenty million, seven hundred thirty thousand, six hundred sixty-one".