20390740537 has 4 divisors (see below), whose sum is σ = 20695080016. Its totient is φ = 20086401060.

The previous prime is 20390740529. The next prime is 20390740541. The reversal of 20390740537 is 73504709302.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20390740537 - 2³ = 20390740529 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20390740537.

It is not an unprimeable number, because it can be changed into a prime (20390740547) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 152169639 + ... + 152169772.

It is an arithmetic number, because the mean of its divisors is an integer number (5173770004).

Almost surely, 2^20390740537 is an apocalyptic number.

It is an amenable number.

20390740537 is a deficient number, since it is larger than the sum of its proper divisors (304339479).

20390740537 is an equidigital number, since it uses as much as digits as its factorization.

20390740537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304339478.

The product of its (nonzero) digits is 158760, while the sum is 40.

The spelling of 20390740537 in words is "twenty billion, three hundred ninety million, seven hundred forty thousand, five hundred thirty-seven".