20487078931 has 4 divisors (see below), whose sum is σ = 22349540664. Its totient is φ = 18624617200.

The previous prime is 20487078929. The next prime is 20487078961. The reversal of 20487078931 is 13987078402.

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 20487078931 - 2¹ = 20487078929 is a prime.

It is a super-2 number, since 2×20487078931² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20487078961) 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, 931230850 + ... + 931230871.

It is an arithmetic number, because the mean of its divisors is an integer number (5587385166).

Almost surely, 2^20487078931 is an apocalyptic number.

20487078931 is a deficient number, since it is larger than the sum of its proper divisors (1862461733).

20487078931 is a wasteful number, since it uses less digits than its factorization.

20487078931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1862461732.

The product of its (nonzero) digits is 677376, while the sum is 49.

The spelling of 20487078931 in words is "twenty billion, four hundred eighty-seven million, seventy-eight thousand, nine hundred thirty-one".