21196749 has 8 divisors (see below), whose sum is σ = 32299840. Its totient is φ = 12112416.

The previous prime is 21196733. The next prime is 21196751. The reversal of 21196749 is 94769112.

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

It is not a de Polignac number, because 21196749 - 2⁴ = 21196733 is a prime.

It is a super-3 number, since 3×21196749³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21196759) 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, 504664 + ... + 504705.

It is an arithmetic number, because the mean of its divisors is an integer number (4037480).

Almost surely, 2^21196749 is an apocalyptic number.

It is an amenable number.

21196749 is a deficient number, since it is larger than the sum of its proper divisors (11103091).

21196749 is a wasteful number, since it uses less digits than its factorization.

21196749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1009379.

The product of its digits is 27216, while the sum is 39.

The square root of 21196749 is about 4603.9927237128. The cubic root of 21196749 is about 276.7513527629.

It can be divided in two parts, 21196 and 749, that added together give a triangular number (21945 = T₂₀₉).

The spelling of 21196749 in words is "twenty-one million, one hundred ninety-six thousand, seven hundred forty-nine".