16921748947 has 4 divisors (see below), whose sum is σ = 16922014480. Its totient is φ = 16921483416.

The previous prime is 16921748941. The next prime is 16921748951. The reversal of 16921748947 is 74984712961.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a 3-Lehmer number, since φ(16921748947) divides (16921748947-1)³.

It is a cyclic number.

It is not a de Polignac number, because 16921748947 - 2¹⁹ = 16921224659 is a prime.

It is a deceptive number, since it divides R_16921748946.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 16921748891 and 16921748900.

It is not an unprimeable number, because it can be changed into a prime (16921748941) 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, 26554 + ... + 185872.

It is an arithmetic number, because the mean of its divisors is an integer number (4230503620).

Almost surely, 2^16921748947 is an apocalyptic number.

16921748947 is the 106213-rd pentagonal number.

16921748947 is a deficient number, since it is larger than the sum of its proper divisors (265533).

16921748947 is a wasteful number, since it uses less digits than its factorization.

16921748947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 265532.

The product of its digits is 6096384, while the sum is 58.

The spelling of 16921748947 in words is "sixteen billion, nine hundred twenty-one million, seven hundred forty-eight thousand, nine hundred forty-seven".