21013554903 has 24 divisors (see below), whose sum is σ = 30910510848. Its totient is φ = 12688434000.

The previous prime is 21013554901. The next prime is 21013554953. The reversal of 21013554903 is 30945531012.

It is not a de Polignac number, because 21013554903 - 2¹ = 21013554901 is a prime.

It is a super-2 number, since 2×21013554903² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21013554901) 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 23 ways as a sum of consecutive naturals, for example, 8433 + ... + 205178.

It is an arithmetic number, because the mean of its divisors is an integer number (1287937952).

Almost surely, 2^21013554903 is an apocalyptic number.

21013554903 is a deficient number, since it is larger than the sum of its proper divisors (9896955945).

21013554903 is a wasteful number, since it uses less digits than its factorization.

21013554903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213907 (or 213896 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 33.

The spelling of 21013554903 in words is "twenty-one billion, thirteen million, five hundred fifty-four thousand, nine hundred three".