21547003829 has 4 divisors (see below), whose sum is σ = 23204465676. Its totient is φ = 19889541984.

The previous prime is 21547003801. The next prime is 21547003837. The reversal of 21547003829 is 92830074512.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11264638225 + 10282365604 = 106135^2 + 101402^2 .

It is not a de Polignac number, because 21547003829 - 2⁸ = 21547003573 is a prime.

It is a super-2 number, since 2×21547003829² (a number of 21 digits) contains 22 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 (21547003729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 828730904 + ... + 828730929.

It is an arithmetic number, because the mean of its divisors is an integer number (5801116419).

Almost surely, 2^21547003829 is an apocalyptic number.

It is an amenable number.

21547003829 is a deficient number, since it is larger than the sum of its proper divisors (1657461847).

21547003829 is a wasteful number, since it uses less digits than its factorization.

21547003829 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1657461846.

The product of its (nonzero) digits is 120960, while the sum is 41.

The spelling of 21547003829 in words is "twenty-one billion, five hundred forty-seven million, three thousand, eight hundred twenty-nine".