21969194 has 32 divisors (see below), whose sum is σ = 37403856. Its totient is φ = 9607680.

The previous prime is 21969193. The next prime is 21969197. The reversal of 21969194 is 49196912.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 1836025 + 20133169 = 1355^2 + 4487^2 .

It is a Harshad number since it is a multiple of its sum of digits (41).

It is not an unprimeable number, because it can be changed into a prime (21969191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39164 + ... + 39720.

Almost surely, 2^21969194 is an apocalyptic number.

21969194 is a deficient number, since it is larger than the sum of its proper divisors (15434662).

21969194 is a wasteful number, since it uses less digits than its factorization.

21969194 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 650.

The product of its digits is 34992, while the sum is 41.

The square root of 21969194 is about 4687.1306787842. The cubic root of 21969194 is about 280.0730846635.

The spelling of 21969194 in words is "twenty-one million, nine hundred sixty-nine thousand, one hundred ninety-four".