16921857877 has 4 divisors (see below), whose sum is σ = 17025673120. Its totient is φ = 16818042636.

The previous prime is 16921857853. The next prime is 16921857893. The reversal of 16921857877 is 77875812961.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 77875812961 = 2333 ⋅33380117.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16921857877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16921855877) 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, 51907377 + ... + 51907702.

It is an arithmetic number, because the mean of its divisors is an integer number (4256418280).

Almost surely, 2^16921857877 is an apocalyptic number.

It is an amenable number.

16921857877 is a deficient number, since it is larger than the sum of its proper divisors (103815243).

16921857877 is a wasteful number, since it uses less digits than its factorization.

16921857877 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103815242.

The product of its digits is 11854080, while the sum is 61.

The spelling of 16921857877 in words is "sixteen billion, nine hundred twenty-one million, eight hundred fifty-seven thousand, eight hundred seventy-seven".