21351005355 has 16 divisors (see below), whose sum is σ = 34183226880. Its totient is φ = 11379996768.

The previous prime is 21351005353. The next prime is 21351005399. The reversal of 21351005355 is 55350015312.

It is not a de Polignac number, because 21351005355 - 2¹ = 21351005353 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21351005353) 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, 425845 + ... + 473334.

It is an arithmetic number, because the mean of its divisors is an integer number (2136451680).

Almost surely, 2^21351005355 is an apocalyptic number.

21351005355 is a deficient number, since it is larger than the sum of its proper divisors (12832221525).

21351005355 is a wasteful number, since it uses less digits than its factorization.

21351005355 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 900770.

The product of its (nonzero) digits is 11250, while the sum is 30.

It can be divided in two parts, 2135 and 1005355, that added together give a triangular number (1007490 = T₁₄₁₉).

The spelling of 21351005355 in words is "twenty-one billion, three hundred fifty-one million, five thousand, three hundred fifty-five".