21769394 has 8 divisors (see below), whose sum is σ = 33536748. Its totient is φ = 10590480.

The previous prime is 21769393. The next prime is 21769411. The reversal of 21769394 is 49396712.

It can be written as a sum of positive squares in 2 ways, for example, as 17749369 + 4020025 = 4213^2 + 2005^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21769393) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 147017 + ... + 147164.

Almost surely, 2^21769394 is an apocalyptic number.

21769394 is a deficient number, since it is larger than the sum of its proper divisors (11767354).

21769394 is a wasteful number, since it uses less digits than its factorization.

21769394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 294220.

The product of its digits is 81648, while the sum is 41.

The square root of 21769394 is about 4665.7683182944. The cubic root of 21769394 is about 279.2214511724.

The spelling of 21769394 in words is "twenty-one million, seven hundred sixty-nine thousand, three hundred ninety-four".