20741661 has 6 divisors (see below), whose sum is σ = 29960190. Its totient is φ = 13827768.

The previous prime is 20741621. The next prime is 20741713. The reversal of 20741661 is 16614702.

It can be written as a sum of positive squares in only one way, i.e., 19316025 + 1425636 = 4395^2 + 1194^2 .

It is not a de Polignac number, because 20741661 - 2¹⁵ = 20708893 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20741621) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1152306 + ... + 1152323.

It is an arithmetic number, because the mean of its divisors is an integer number (4993365).

Almost surely, 2^20741661 is an apocalyptic number.

It is an amenable number.

20741661 is a deficient number, since it is larger than the sum of its proper divisors (9218529).

20741661 is a wasteful number, since it uses less digits than its factorization.

20741661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2304635 (or 2304632 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 20741661 is about 4554.3013734271. The cubic root of 20741661 is about 274.7564168151.

The spelling of 20741661 in words is "twenty million, seven hundred forty-one thousand, six hundred sixty-one".