20427963491 has 4 divisors (see below), whose sum is σ = 21999345312. Its totient is φ = 18856581672.

The previous prime is 20427963473. The next prime is 20427963511. The reversal of 20427963491 is 19436972402.

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 20427963491 - 2¹⁴ = 20427947107 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20427963461) 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, 785690891 + ... + 785690916.

It is an arithmetic number, because the mean of its divisors is an integer number (5499836328).

Almost surely, 2^20427963491 is an apocalyptic number.

20427963491 is a deficient number, since it is larger than the sum of its proper divisors (1571381821).

20427963491 is a wasteful number, since it uses less digits than its factorization.

20427963491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1571381820.

The product of its (nonzero) digits is 653184, while the sum is 47.

The spelling of 20427963491 in words is "twenty billion, four hundred twenty-seven million, nine hundred sixty-three thousand, four hundred ninety-one".