20757591973 has 4 divisors (see below), whose sum is σ = 21097880428. Its totient is φ = 20417303520.

The previous prime is 20757591949. The next prime is 20757591983. The reversal of 20757591973 is 37919575702.

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 10828067364 + 9929524609 = 104058^2 + 99647^2 .

It is a cyclic number.

It is not a de Polignac number, because 20757591973 - 2⁹ = 20757591461 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20757591913) 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, 170144136 + ... + 170144257.

It is an arithmetic number, because the mean of its divisors is an integer number (5274470107).

Almost surely, 2^20757591973 is an apocalyptic number.

It is an amenable number.

20757591973 is a deficient number, since it is larger than the sum of its proper divisors (340288455).

20757591973 is an equidigital number, since it uses as much as digits as its factorization.

20757591973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340288454.

The product of its (nonzero) digits is 4167450, while the sum is 55.

The spelling of 20757591973 in words is "twenty billion, seven hundred fifty-seven million, five hundred ninety-one thousand, nine hundred seventy-three".