20035661 has 4 divisors (see below), whose sum is σ = 20095452. Its totient is φ = 19975872.

The previous prime is 20035657. The next prime is 20035669. The reversal of 20035661 is 16653002.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11095561 + 8940100 = 3331^2 + 2990^2 .

It is a cyclic number.

It is not a de Polignac number, because 20035661 - 2² = 20035657 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20035669) 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, 29390 + ... + 30063.

It is an arithmetic number, because the mean of its divisors is an integer number (5023863).

Almost surely, 2^20035661 is an apocalyptic number.

It is an amenable number.

20035661 is a deficient number, since it is larger than the sum of its proper divisors (59791).

20035661 is an equidigital number, since it uses as much as digits as its factorization.

20035661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59790.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 20035661 is about 4476.1212003251. The cubic root of 20035661 is about 271.6029972781.

Adding to 20035661 its reverse (16653002), we get a palindrome (36688663).

The spelling of 20035661 in words is "twenty million, thirty-five thousand, six hundred sixty-one".