21019347 has 12 divisors (see below), whose sum is σ = 31102344. Its totient is φ = 13670880.

The previous prime is 21019331. The next prime is 21019363. The reversal of 21019347 is 74391012.

It is an interprime number because it is at equal distance from previous prime (21019331) and next prime (21019363).

It is not a de Polignac number, because 21019347 - 2⁴ = 21019331 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21019347.

It is not an unprimeable number, because it can be changed into a prime (21019247) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28113 + ... + 28850.

It is an arithmetic number, because the mean of its divisors is an integer number (2591862).

Almost surely, 2^21019347 is an apocalyptic number.

21019347 is a deficient number, since it is larger than the sum of its proper divisors (10082997).

21019347 is a wasteful number, since it uses less digits than its factorization.

21019347 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57010 (or 57007 counting only the distinct ones).

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

The square root of 21019347 is about 4584.6861397483. The cubic root of 21019347 is about 275.9771168804.

The spelling of 21019347 in words is "twenty-one million, nineteen thousand, three hundred forty-seven".