21031355251603 has 16 divisors (see below), whose sum is σ = 22279707600480. Its totient is φ = 19818606721536.

The previous prime is 21031355251601. The next prime is 21031355251609. The reversal of 21031355251603 is 30615255313012.

It is a cyclic number.

It is not a de Polignac number, because 21031355251603 - 2¹ = 21031355251601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21031355251601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4884400 + ... + 8119117.

It is an arithmetic number, because the mean of its divisors is an integer number (1392481725030).

Almost surely, 2^{21031355251603} is an apocalyptic number.

21031355251603 is a deficient number, since it is larger than the sum of its proper divisors (1248352348877).

21031355251603 is a wasteful number, since it uses less digits than its factorization.

21031355251603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13004886.

The product of its (nonzero) digits is 81000, while the sum is 37.

The spelling of 21031355251603 in words is "twenty-one trillion, thirty-one billion, three hundred fifty-five million, two hundred fifty-one thousand, six hundred three".