21919071 has 8 divisors (see below), whose sum is σ = 29276464. Its totient is φ = 14587200.

The previous prime is 21919063. The next prime is 21919081. The reversal of 21919071 is 17091912.

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

It is not a de Polignac number, because 21919071 - 2³ = 21919063 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21919021) 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, 4276 + ... + 7881.

It is an arithmetic number, because the mean of its divisors is an integer number (3659558).

Almost surely, 2^21919071 is an apocalyptic number.

21919071 is a deficient number, since it is larger than the sum of its proper divisors (7357393).

21919071 is a wasteful number, since it uses less digits than its factorization.

21919071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12761.

The product of its (nonzero) digits is 1134, while the sum is 30.

The square root of 21919071 is about 4681.7807509536. The cubic root of 21919071 is about 279.8599256857.

The spelling of 21919071 in words is "twenty-one million, nine hundred nineteen thousand, seventy-one".