20489691 has 4 divisors (see below), whose sum is σ = 27319592. Its totient is φ = 13659792.

The previous prime is 20489683. The next prime is 20489699. The reversal of 20489691 is 19698402.

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

It is an interprime number because it is at equal distance from previous prime (20489683) and next prime (20489699).

It is not a de Polignac number, because 20489691 - 2³ = 20489683 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20489699) 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, 3414946 + ... + 3414951.

It is an arithmetic number, because the mean of its divisors is an integer number (6829898).

Almost surely, 2^20489691 is an apocalyptic number.

20489691 is a deficient number, since it is larger than the sum of its proper divisors (6829901).

20489691 is an equidigital number, since it uses as much as digits as its factorization.

20489691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6829900.

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 20489691 is about 4526.5539873065. The cubic root of 20489691 is about 273.6392992906.

The spelling of 20489691 in words is "twenty million, four hundred eighty-nine thousand, six hundred ninety-one".