20402537 has 2 divisors, whose sum is σ = 20402538. Its totient is φ = 20402536.

The previous prime is 20402531. The next prime is 20402563. The reversal of 20402537 is 73520402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20394256 + 8281 = 4516^2 + 91^2 .

It is a cyclic number.

It is not a de Polignac number, because 20402537 - 2⁴ = 20402521 is a prime.

It is a Chen prime.

It is equal to p_1294511 and since 20402537 and 1294511 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (20402531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10201268 + 10201269.

It is an arithmetic number, because the mean of its divisors is an integer number (10201269).

Almost surely, 2^20402537 is an apocalyptic number.

It is an amenable number.

20402537 is a deficient number, since it is larger than the sum of its proper divisors (1).

20402537 is an equidigital number, since it uses as much as digits as its factorization.

20402537 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1680, while the sum is 23.

The square root of 20402537 is about 4516.9167581438. The cubic root of 20402537 is about 273.2507680756.

Adding to 20402537 its reverse (73520402), we get a palindrome (93922939).

The spelling of 20402537 in words is "twenty million, four hundred two thousand, five hundred thirty-seven".