21960291 has 8 divisors (see below), whose sum is σ = 29342464. Its totient is φ = 14609160.

The previous prime is 21960287. The next prime is 21960293. The reversal of 21960291 is 19206912.

It is a happy number.

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

It is not a de Polignac number, because 21960291 - 2² = 21960287 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21960293) 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 7 ways as a sum of consecutive naturals, for example, 6055 + ... + 8976.

It is an arithmetic number, because the mean of its divisors is an integer number (3667808).

Almost surely, 2^21960291 is an apocalyptic number.

21960291 is a deficient number, since it is larger than the sum of its proper divisors (7382173).

21960291 is a wasteful number, since it uses less digits than its factorization.

21960291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15521.

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 21960291 is about 4686.1808543845. The cubic root of 21960291 is about 280.0352464133.

The spelling of 21960291 in words is "twenty-one million, nine hundred sixty thousand, two hundred ninety-one".