20399636887 has 8 divisors (see below), whose sum is σ = 23325667200. Its totient is φ = 17476555704.

The previous prime is 20399636849. The next prime is 20399636909. The reversal of 20399636887 is 78863699302.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20399636887 - 2⁷ = 20399636759 is a prime.

It is a super-2 number, since 2×20399636887² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20399636827) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 722437 + ... + 750142.

It is an arithmetic number, because the mean of its divisors is an integer number (2915708400).

Almost surely, 2^20399636887 is an apocalyptic number.

20399636887 is a deficient number, since it is larger than the sum of its proper divisors (2926030313).

20399636887 is a wasteful number, since it uses less digits than its factorization.

20399636887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1474565.

The product of its (nonzero) digits is 23514624, while the sum is 61.

The spelling of 20399636887 in words is "twenty billion, three hundred ninety-nine million, six hundred thirty-six thousand, eight hundred eighty-seven".