21345789 has 8 divisors (see below), whose sum is σ = 29155392. Its totient is φ = 13883360.

The previous prime is 21345767. The next prime is 21345809. The reversal of 21345789 is 98754312.

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 21345789 - 2⁵ = 21345757 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21345719) 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, 86649 + ... + 86894.

It is an arithmetic number, because the mean of its divisors is an integer number (3644424).

Almost surely, 2^21345789 is an apocalyptic number.

It is an amenable number.

21345789 is a deficient number, since it is larger than the sum of its proper divisors (7809603).

21345789 is a wasteful number, since it uses less digits than its factorization.

21345789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173587.

The product of its digits is 60480, while the sum is 39.

The square root of 21345789 is about 4620.1503222298. The cubic root of 21345789 is about 277.3984759694.

The spelling of 21345789 in words is "twenty-one million, three hundred forty-five thousand, seven hundred eighty-nine".