20061640537 has 4 divisors (see below), whose sum is σ = 20603847076. Its totient is φ = 19519434000.

The previous prime is 20061640531. The next prime is 20061640541. The reversal of 20061640537 is 73504616002.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16083058761 + 3978581776 = 126819^2 + 63076^2 .

It is a cyclic number.

It is not a de Polignac number, because 20061640537 - 2¹⁹ = 20061116249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20061640531) 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, 271103214 + ... + 271103287.

It is an arithmetic number, because the mean of its divisors is an integer number (5150961769).

Almost surely, 2^20061640537 is an apocalyptic number.

It is an amenable number.

20061640537 is a deficient number, since it is larger than the sum of its proper divisors (542206539).

20061640537 is an equidigital number, since it uses as much as digits as its factorization.

20061640537 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 542206538.

The product of its (nonzero) digits is 30240, while the sum is 34.

The spelling of 20061640537 in words is "twenty billion, sixty-one million, six hundred forty thousand, five hundred thirty-seven".