21764369 has 8 divisors (see below), whose sum is σ = 25139808. Its totient is φ = 18621760.

The previous prime is 21764341. The next prime is 21764381. The reversal of 21764369 is 96346712.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21764369 is a prime.

It is a super-2 number, since 2×21764369² = 947375515936322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21764669) 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, 58007 + ... + 58380.

It is an arithmetic number, because the mean of its divisors is an integer number (3142476).

Almost surely, 2^21764369 is an apocalyptic number.

It is an amenable number.

21764369 is a deficient number, since it is larger than the sum of its proper divisors (3375439).

21764369 is a wasteful number, since it uses less digits than its factorization.

21764369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116415.

The product of its digits is 54432, while the sum is 38.

The square root of 21764369 is about 4665.2297906963. The cubic root of 21764369 is about 279.1999654149.

It can be divided in two parts, 217643 and 69, that added together give a palindrome (217712).

The spelling of 21764369 in words is "twenty-one million, seven hundred sixty-four thousand, three hundred sixty-nine".