20642416537 has 2 divisors, whose sum is σ = 20642416538. Its totient is φ = 20642416536.

The previous prime is 20642416519. The next prime is 20642416607. The reversal of 20642416537 is 73561424602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14646082441 + 5996334096 = 121021^2 + 77436^2 .

It is a cyclic number.

It is not a de Polignac number, because 20642416537 - 2²³ = 20634027929 is a prime.

It is a super-2 number, since 2×20642416537² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20642416537.

It is not a weakly prime, because it can be changed into another prime (20642416237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10321208268 + 10321208269.

It is an arithmetic number, because the mean of its divisors is an integer number (10321208269).

Almost surely, 2^20642416537 is an apocalyptic number.

It is an amenable number.

20642416537 is a deficient number, since it is larger than the sum of its proper divisors (1).

20642416537 is an equidigital number, since it uses as much as digits as its factorization.

20642416537 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 241920, while the sum is 40.

The spelling of 20642416537 in words is "twenty billion, six hundred forty-two million, four hundred sixteen thousand, five hundred thirty-seven".