21531422111555 has 16 divisors (see below), whose sum is σ = 25899960129888. Its totient is φ = 17183638080000.

The previous prime is 21531422111519. The next prime is 21531422111567. The reversal of 21531422111555 is 55511122413512.

It is not a de Polignac number, because 21531422111555 - 2¹⁰ = 21531422110531 is a prime.

It is a Duffinian 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, 68046260 + ... + 68361950.

It is an arithmetic number, because the mean of its divisors is an integer number (1618747508118).

Almost surely, 2^{21531422111555} is an apocalyptic number.

21531422111555 is a deficient number, since it is larger than the sum of its proper divisors (4368538018333).

21531422111555 is a wasteful number, since it uses less digits than its factorization.

21531422111555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 348518.

The product of its digits is 60000, while the sum is 38.

The spelling of 21531422111555 in words is "twenty-one trillion, five hundred thirty-one billion, four hundred twenty-two million, one hundred eleven thousand, five hundred fifty-five".