20021009537 has 2 divisors, whose sum is σ = 20021009538. Its totient is φ = 20021009536.

The previous prime is 20021009509. The next prime is 20021009543. The reversal of 20021009537 is 73590012002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17057404816 + 2963604721 = 130604^2 + 54439^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20021009537 is a prime.

It is not a weakly prime, because it can be changed into another prime (20021002537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10010504768 + 10010504769.

It is an arithmetic number, because the mean of its divisors is an integer number (10010504769).

Almost surely, 2^20021009537 is an apocalyptic number.

It is an amenable number.

20021009537 is a deficient number, since it is larger than the sum of its proper divisors (1).

20021009537 is an equidigital number, since it uses as much as digits as its factorization.

20021009537 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3780, while the sum is 29.

The spelling of 20021009537 in words is "twenty billion, twenty-one million, nine thousand, five hundred thirty-seven".