21203542175655 has 16 divisors (see below), whose sum is σ = 38772191407104. Its totient is φ = 9693047851680.

The previous prime is 21203542175551. The next prime is 21203542175681. The reversal of 21203542175655 is 55657124530212.

It is not a de Polignac number, because 21203542175655 - 2⁹ = 21203542175143 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 100969248351 + ... + 100969248560.

It is an arithmetic number, because the mean of its divisors is an integer number (2423261962944).

Almost surely, 2^{21203542175655} is an apocalyptic number.

21203542175655 is a deficient number, since it is larger than the sum of its proper divisors (17568649231449).

21203542175655 is a wasteful number, since it uses less digits than its factorization.

21203542175655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 201938496926.

The product of its (nonzero) digits is 2520000, while the sum is 48.

The spelling of 21203542175655 in words is "twenty-one trillion, two hundred three billion, five hundred forty-two million, one hundred seventy-five thousand, six hundred fifty-five".