20591611739 has 4 divisors (see below), whose sum is σ = 21148141824. Its totient is φ = 20035081656.

The previous prime is 20591611693. The next prime is 20591611759. The reversal of 20591611739 is 93711619502.

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

It is a cyclic number.

It is not a de Polignac number, because 20591611739 - 2³² = 16296644443 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 20591611739.

It is not an unprimeable number, because it can be changed into a prime (20591611759) 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, 278264987 + ... + 278265060.

It is an arithmetic number, because the mean of its divisors is an integer number (5287035456).

Almost surely, 2^20591611739 is an apocalyptic number.

20591611739 is a deficient number, since it is larger than the sum of its proper divisors (556530085).

20591611739 is an equidigital number, since it uses as much as digits as its factorization.

20591611739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 556530084.

The product of its (nonzero) digits is 102060, while the sum is 44.

The spelling of 20591611739 in words is "twenty billion, five hundred ninety-one million, six hundred eleven thousand, seven hundred thirty-nine".