20437381 has 2 divisors, whose sum is σ = 20437382. Its totient is φ = 20437380.

The previous prime is 20437327. The next prime is 20437453. The reversal of 20437381 is 18373402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17430625 + 3006756 = 4175^2 + 1734^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20437381 is a prime.

It is a super-2 number, since 2×20437381² = 835373084278322, which contains 22 as substring.

It is equal to p_1296541 and since 20437381 and 1296541 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20437301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10218690 + 10218691.

It is an arithmetic number, because the mean of its divisors is an integer number (10218691).

Almost surely, 2^20437381 is an apocalyptic number.

It is an amenable number.

20437381 is a deficient number, since it is larger than the sum of its proper divisors (1).

20437381 is an equidigital number, since it uses as much as digits as its factorization.

20437381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 20437381 is about 4520.7721685570. The cubic root of 20437381 is about 273.4062346031.

The spelling of 20437381 in words is "twenty million, four hundred thirty-seven thousand, three hundred eighty-one".