6453721667 has 4 divisors (see below), whose sum is σ = 6563106840. Its totient is φ = 6344336496.

The previous prime is 6453721643. The next prime is 6453721709. The reversal of 6453721667 is 7661273546.

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 6453721667 - 2¹⁴ = 6453705283 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6453721627) 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, 54692498 + ... + 54692615.

It is an arithmetic number, because the mean of its divisors is an integer number (1640776710).

Almost surely, 2^6453721667 is an apocalyptic number.

6453721667 is a deficient number, since it is larger than the sum of its proper divisors (109385173).

6453721667 is a wasteful number, since it uses less digits than its factorization.

6453721667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109385172.

The product of its digits is 1270080, while the sum is 47.

The square root of 6453721667 is about 80335.0587663941. The cubic root of 6453721667 is about 1861.8159382805.

The spelling of 6453721667 in words is "six billion, four hundred fifty-three million, seven hundred twenty-one thousand, six hundred sixty-seven".