20021137 has 2 divisors, whose sum is σ = 20021138. Its totient is φ = 20021136.

The previous prime is 20021093. The next prime is 20021147. The reversal of 20021137 is 73112002.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18931201 + 1089936 = 4351^2 + 1044^2 .

It is a cyclic number.

It is not a de Polignac number, because 20021137 - 2¹⁵ = 19988369 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20021137.

It is not a weakly prime, because it can be changed into another prime (20021147) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10010568 + 10010569.

It is an arithmetic number, because the mean of its divisors is an integer number (10010569).

Almost surely, 2^20021137 is an apocalyptic number.

It is an amenable number.

20021137 is a deficient number, since it is larger than the sum of its proper divisors (1).

20021137 is an equidigital number, since it uses as much as digits as its factorization.

20021137 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 84, while the sum is 16.

The square root of 20021137 is about 4474.4985193874. The cubic root of 20021137 is about 271.5373524010.

Adding to 20021137 its reverse (73112002), we get a palindrome (93133139).

The spelling of 20021137 in words is "twenty million, twenty-one thousand, one hundred thirty-seven".