21553703 has 8 divisors (see below), whose sum is σ = 22142160. Its totient is φ = 20972800.

The previous prime is 21553643. The next prime is 21553717. The reversal of 21553703 is 30735512.

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 21553703 - 2²⁰ = 20505127 is a prime.

It is a super-2 number, since 2×21553703² = 929124226024418, which 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 (21553403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4151 + ... + 7767.

It is an arithmetic number, because the mean of its divisors is an integer number (2767770).

Almost surely, 2^21553703 is an apocalyptic number.

21553703 is a deficient number, since it is larger than the sum of its proper divisors (588457).

21553703 is a wasteful number, since it uses less digits than its factorization.

21553703 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3777.

The product of its (nonzero) digits is 3150, while the sum is 26.

The square root of 21553703 is about 4642.5965795016. The cubic root of 21553703 is about 278.2962139494.

The spelling of 21553703 in words is "twenty-one million, five hundred fifty-three thousand, seven hundred three".