21009990477503 has 8 divisors (see below), whose sum is σ = 21403642294800. Its totient is φ = 20617590336448.

The previous prime is 21009990477491. The next prime is 21009990477521. The reversal of 21009990477503 is 30577409990012.

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 21009990477503 - 2⁶ = 21009990477439 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 (21009990477403) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 312885176 + ... + 312952317.

It is an arithmetic number, because the mean of its divisors is an integer number (2675455286850).

Almost surely, 2^{21009990477503} is an apocalyptic number.

21009990477503 is a deficient number, since it is larger than the sum of its proper divisors (393651817297).

21009990477503 is an equidigital number, since it uses as much as digits as its factorization.

21009990477503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 625838121.

The product of its (nonzero) digits is 4286520, while the sum is 56.

The spelling of 21009990477503 in words is "twenty-one trillion, nine billion, nine hundred ninety million, four hundred seventy-seven thousand, five hundred three".