21347765 has 8 divisors (see below), whose sum is σ = 25660800. Its totient is φ = 17049232.

The previous prime is 21347723. The next prime is 21347771. The reversal of 21347765 is 56774312.

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 21347765 - 2⁶ = 21347701 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 65 + ... + 6534.

It is an arithmetic number, because the mean of its divisors is an integer number (3207600).

Almost surely, 2^21347765 is an apocalyptic number.

It is an amenable number.

21347765 is a deficient number, since it is larger than the sum of its proper divisors (4313035).

21347765 is an equidigital number, since it uses as much as digits as its factorization.

21347765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7251.

The product of its digits is 35280, while the sum is 35.

The square root of 21347765 is about 4620.3641631369. The cubic root of 21347765 is about 277.4070353856.

The spelling of 21347765 in words is "twenty-one million, three hundred forty-seven thousand, seven hundred sixty-five".