21740319 has 20 divisors (see below), whose sum is σ = 32822944. Its totient is φ = 14338944.

The previous prime is 21740317. The next prime is 21740347. The reversal of 21740319 is 91304712.

It is not a de Polignac number, because 21740319 - 2¹ = 21740317 is a prime.

It is a super-2 number, since 2×21740319² = 945282940443522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21740292 and 21740301.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21740317) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 6474 + ... + 9240.

Almost surely, 2^21740319 is an apocalyptic number.

21740319 is a deficient number, since it is larger than the sum of its proper divisors (11082625).

21740319 is an equidigital number, since it uses as much as digits as its factorization.

21740319 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2876 (or 2867 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 21740319 is about 4662.6514988792. The cubic root of 21740319 is about 279.0970872658.

The spelling of 21740319 in words is "twenty-one million, seven hundred forty thousand, three hundred nineteen".