20507040137 has 4 divisors (see below), whose sum is σ = 20535964740. Its totient is φ = 20478115536.

The previous prime is 20507040091. The next prime is 20507040181. The reversal of 20507040137 is 73104070502.

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 10027218496 + 10479821641 = 100136^2 + 102371^2 .

It is a cyclic number.

It is not a de Polignac number, because 20507040137 - 2¹⁶ = 20506974601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20507040187) 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, 14461238 + ... + 14462655.

It is an arithmetic number, because the mean of its divisors is an integer number (5133991185).

Almost surely, 2^20507040137 is an apocalyptic number.

It is an amenable number.

20507040137 is a deficient number, since it is larger than the sum of its proper divisors (28924603).

20507040137 is an equidigital number, since it uses as much as digits as its factorization.

20507040137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28924602.

The product of its (nonzero) digits is 5880, while the sum is 29.

The spelling of 20507040137 in words is "twenty billion, five hundred seven million, forty thousand, one hundred thirty-seven".