21349471 has 8 divisors (see below), whose sum is σ = 25082064. Its totient is φ = 17915520.

The previous prime is 21349459. The next prime is 21349511. The reversal of 21349471 is 17494312.

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

It is a cyclic number.

It is not a de Polignac number, because 21349471 - 2¹¹ = 21347423 is a prime.

It is a super-3 number, since 3×21349471³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21349571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 74506 + ... + 74791.

It is an arithmetic number, because the mean of its divisors is an integer number (3135258).

Almost surely, 2^21349471 is an apocalyptic number.

21349471 is a deficient number, since it is larger than the sum of its proper divisors (3732593).

21349471 is a wasteful number, since it uses less digits than its factorization.

21349471 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149321.

The product of its digits is 6048, while the sum is 31.

The square root of 21349471 is about 4620.5487769312. The cubic root of 21349471 is about 277.4144248211.

The spelling of 21349471 in words is "twenty-one million, three hundred forty-nine thousand, four hundred seventy-one".