21901306 has 8 divisors (see below), whose sum is σ = 37545120. Its totient is φ = 9386268.

The previous prime is 21901291. The next prime is 21901381. The reversal of 21901306 is 60310912.

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 782176 + ... + 782203.

It is an arithmetic number, because the mean of its divisors is an integer number (4693140).

Almost surely, 2^21901306 is an apocalyptic number.

21901306 is a deficient number, since it is larger than the sum of its proper divisors (15643814).

21901306 is a wasteful number, since it uses less digits than its factorization.

21901306 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1564388.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 21901306 is about 4679.8831181986. The cubic root of 21901306 is about 279.7842981595.

The spelling of 21901306 in words is "twenty-one million, nine hundred one thousand, three hundred six".