20726134057 has 4 divisors (see below), whose sum is σ = 20726866116. Its totient is φ = 20725402000.

The previous prime is 20726133997. The next prime is 20726134061. The reversal of 20726134057 is 75043162702.

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 3192137001 + 17533997056 = 56499^2 + 132416^2 .

It is a cyclic number.

It is not a de Polignac number, because 20726134057 - 2¹⁹ = 20725609769 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20726134357) 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, 321778 + ... + 380779.

It is an arithmetic number, because the mean of its divisors is an integer number (5181716529).

Almost surely, 2^20726134057 is an apocalyptic number.

It is an amenable number.

20726134057 is a deficient number, since it is larger than the sum of its proper divisors (732059).

20726134057 is an equidigital number, since it uses as much as digits as its factorization.

20726134057 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 732058.

The product of its (nonzero) digits is 70560, while the sum is 37.

Adding to 20726134057 its reverse (75043162702), we get a palindrome (95769296759).

The spelling of 20726134057 in words is "twenty billion, seven hundred twenty-six million, one hundred thirty-four thousand, fifty-seven".