1868721667 has 4 divisors (see below), whose sum is σ = 1919227696. Its totient is φ = 1818215640.

The previous prime is 1868721661. The next prime is 1868721683. The reversal of 1868721667 is 7661278681.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1868721667 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1868721661) 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, 25252959 + ... + 25253032.

It is an arithmetic number, because the mean of its divisors is an integer number (479806924).

Almost surely, 2^1868721667 is an apocalyptic number.

1868721667 is a deficient number, since it is larger than the sum of its proper divisors (50506029).

1868721667 is an equidigital number, since it uses as much as digits as its factorization.

1868721667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50506028.

The product of its digits is 1354752, while the sum is 52.

The square root of 1868721667 is about 43228.7134552950. The cubic root of 1868721667 is about 1231.7281691675.

The spelling of 1868721667 in words is "one billion, eight hundred sixty-eight million, seven hundred twenty-one thousand, six hundred sixty-seven".