20248836491 has 4 divisors (see below), whose sum is σ = 21806439312. Its totient is φ = 18691233672.

The previous prime is 20248836473. The next prime is 20248836511. The reversal of 20248836491 is 19463884202.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20248836491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20248836791) 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, 778801391 + ... + 778801416.

It is an arithmetic number, because the mean of its divisors is an integer number (5451609828).

Almost surely, 2^20248836491 is an apocalyptic number.

20248836491 is a deficient number, since it is larger than the sum of its proper divisors (1557602821).

20248836491 is a wasteful number, since it uses less digits than its factorization.

20248836491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1557602820.

The product of its (nonzero) digits is 663552, while the sum is 47.

Subtracting from 20248836491 its reverse (19463884202), we obtain a square (784952289 = 28017²).

The spelling of 20248836491 in words is "twenty billion, two hundred forty-eight million, eight hundred thirty-six thousand, four hundred ninety-one".