21419391 has 8 divisors (see below), whose sum is σ = 32639104. Its totient is φ = 12239640.

The previous prime is 21419389. The next prime is 21419393. The reversal of 21419391 is 19391412.

It is an interprime number because it is at equal distance from previous prime (21419389) and next prime (21419393).

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

It is not a de Polignac number, because 21419391 - 2¹ = 21419389 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 (21419393) 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, 509965 + ... + 510006.

It is an arithmetic number, because the mean of its divisors is an integer number (4079888).

Almost surely, 2^21419391 is an apocalyptic number.

21419391 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21419391 is a deficient number, since it is larger than the sum of its proper divisors (11219713).

21419391 is a wasteful number, since it uses less digits than its factorization.

21419391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1019981.

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

The square root of 21419391 is about 4628.1087930169. The cubic root of 21419391 is about 277.7169409821.

The spelling of 21419391 in words is "twenty-one million, four hundred nineteen thousand, three hundred ninety-one".