20435681 has 4 divisors (see below), whose sum is σ = 23355072. Its totient is φ = 17516292.

The previous prime is 20435677. The next prime is 20435689. The reversal of 20435681 is 18653402.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20435681 - 2² = 20435677 is a prime.

It is a super-2 number, since 2×20435681² = 835234115867522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20435689) 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, 1459685 + ... + 1459698.

It is an arithmetic number, because the mean of its divisors is an integer number (5838768).

Almost surely, 2^20435681 is an apocalyptic number.

It is an amenable number.

20435681 is a deficient number, since it is larger than the sum of its proper divisors (2919391).

20435681 is an equidigital number, since it uses as much as digits as its factorization.

20435681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2919390.

The product of its (nonzero) digits is 5760, while the sum is 29.

The square root of 20435681 is about 4520.5841436699. The cubic root of 20435681 is about 273.3986536663.

The spelling of 20435681 in words is "twenty million, four hundred thirty-five thousand, six hundred eighty-one".