21919461 has 8 divisors (see below), whose sum is σ = 29938944. Its totient is φ = 14256480.

The previous prime is 21919459. The next prime is 21919481. The reversal of 21919461 is 16491912.

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

It is not a de Polignac number, because 21919461 - 2¹ = 21919459 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21919411) 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, 88981 + ... + 89226.

It is an arithmetic number, because the mean of its divisors is an integer number (3742368).

Almost surely, 2^21919461 is an apocalyptic number.

It is an amenable number.

21919461 is a deficient number, since it is larger than the sum of its proper divisors (8019483).

21919461 is a wasteful number, since it uses less digits than its factorization.

21919461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178251.

The product of its digits is 3888, while the sum is 33.

The square root of 21919461 is about 4681.8224015868. The cubic root of 21919461 is about 279.8615854994.

The spelling of 21919461 in words is "twenty-one million, nine hundred nineteen thousand, four hundred sixty-one".