21390167689 has 8 divisors (see below), whose sum is σ = 23361346368. Its totient is φ = 19423425360.

The previous prime is 21390167651. The next prime is 21390167699. The reversal of 21390167689 is 98676109312.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21390167689 - 2⁹ = 21390167177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21390167609) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1098997 + ... + 1118290.

It is an arithmetic number, because the mean of its divisors is an integer number (2920168296).

Almost surely, 2^21390167689 is an apocalyptic number.

It is an amenable number.

21390167689 is a deficient number, since it is larger than the sum of its proper divisors (1971178679).

21390167689 is a wasteful number, since it uses less digits than its factorization.

21390167689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2218175.

The product of its (nonzero) digits is 979776, while the sum is 52.

The spelling of 21390167689 in words is "twenty-one billion, three hundred ninety million, one hundred sixty-seven thousand, six hundred eighty-nine".