21829903 has 4 divisors (see below), whose sum is σ = 22001920. Its totient is φ = 21657888.

The previous prime is 21829897. The next prime is 21829933. The reversal of 21829903 is 30992812.

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

It is a cyclic number.

It is not a de Polignac number, because 21829903 - 2²¹ = 19732751 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21829933) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85818 + ... + 86071.

It is an arithmetic number, because the mean of its divisors is an integer number (5500480).

Almost surely, 2^21829903 is an apocalyptic number.

21829903 is a deficient number, since it is larger than the sum of its proper divisors (172017).

21829903 is a wasteful number, since it uses less digits than its factorization.

21829903 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172016.

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 21829903 is about 4672.2481740593. The cubic root of 21829903 is about 279.4799146689.

The spelling of 21829903 in words is "twenty-one million, eight hundred twenty-nine thousand, nine hundred three".