21715154067 has 4 divisors (see below), whose sum is σ = 28953538760. Its totient is φ = 14476769376.

The previous prime is 21715154039. The next prime is 21715154077. The reversal of 21715154067 is 76045151712.

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

It is not a de Polignac number, because 21715154067 - 2⁷ = 21715153939 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21715154077) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3619192342 + ... + 3619192347.

It is an arithmetic number, because the mean of its divisors is an integer number (7238384690).

Almost surely, 2^21715154067 is an apocalyptic number.

21715154067 is a deficient number, since it is larger than the sum of its proper divisors (7238384693).

21715154067 is an equidigital number, since it uses as much as digits as its factorization.

21715154067 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7238384692.

The product of its (nonzero) digits is 58800, while the sum is 39.

The spelling of 21715154067 in words is "twenty-one billion, seven hundred fifteen million, one hundred fifty-four thousand, sixty-seven".