21469539 has 16 divisors (see below), whose sum is σ = 35232512. Its totient is φ = 11324448.

The previous prime is 21469517. The next prime is 21469543. The reversal of 21469539 is 93596412.

It is not a de Polignac number, because 21469539 - 2⁹ = 21469027 is a prime.

It is a super-2 number, since 2×21469539² = 921882209745042, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a junction number, because it is equal to n+sod(n) for n = 21469497 and 21469506.

It is not an unprimeable number, because it can be changed into a prime (21469579) 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 15 ways as a sum of consecutive naturals, for example, 39049 + ... + 39594.

It is an arithmetic number, because the mean of its divisors is an integer number (2202032).

Almost surely, 2^21469539 is an apocalyptic number.

21469539 is a deficient number, since it is larger than the sum of its proper divisors (13762973).

21469539 is a wasteful number, since it uses less digits than its factorization.

21469539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78666.

The product of its digits is 58320, while the sum is 39.

The square root of 21469539 is about 4633.5233893874. The cubic root of 21469539 is about 277.9335063439.

The spelling of 21469539 in words is "twenty-one million, four hundred sixty-nine thousand, five hundred thirty-nine".