20440691 has 2 divisors, whose sum is σ = 20440692. Its totient is φ = 20440690.

The previous prime is 20440649. The next prime is 20440699. The reversal of 20440691 is 19604402.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20440691 - 2¹⁴ = 20424307 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20440691.

It is not a weakly prime, because it can be changed into another prime (20440699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10220345 + 10220346.

It is an arithmetic number, because the mean of its divisors is an integer number (10220346).

Almost surely, 2^20440691 is an apocalyptic number.

20440691 is a deficient number, since it is larger than the sum of its proper divisors (1).

20440691 is an equidigital number, since it uses as much as digits as its factorization.

20440691 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 20440691 is about 4521.1382416378. The cubic root of 20440691 is about 273.4209939272.

The spelling of 20440691 in words is "twenty million, four hundred forty thousand, six hundred ninety-one".