20437861 has 2 divisors, whose sum is σ = 20437862. Its totient is φ = 20437860.

The previous prime is 20437849. The next prime is 20437873. The reversal of 20437861 is 16873402.

It is a balanced prime because it is at equal distance from previous prime (20437849) and next prime (20437873).

It can be written as a sum of positive squares in only one way, i.e., 18922500 + 1515361 = 4350^2 + 1231^2 .

It is a cyclic number.

It is not a de Polignac number, because 20437861 - 2⁵ = 20437829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20437811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10218930 + 10218931.

It is an arithmetic number, because the mean of its divisors is an integer number (10218931).

Almost surely, 2^20437861 is an apocalyptic number.

It is an amenable number.

20437861 is a deficient number, since it is larger than the sum of its proper divisors (1).

20437861 is an equidigital number, since it uses as much as digits as its factorization.

20437861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 31.

The square root of 20437861 is about 4520.8252565212. The cubic root of 20437861 is about 273.4083750269.

The spelling of 20437861 in words is "twenty million, four hundred thirty-seven thousand, eight hundred sixty-one".