213581124561 has 32 divisors (see below), whose sum is σ = 350942054400. Its totient is φ = 112802785920.

The previous prime is 213581124541. The next prime is 213581124629. The reversal of 213581124561 is 165421185312.

It is not a de Polignac number, because 213581124561 - 2¹⁵ = 213581091793 is a prime.

It is not an unprimeable number, because it can be changed into a prime (213581124541) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6511581 + ... + 6544298.

It is an arithmetic number, because the mean of its divisors is an integer number (10966939200).

Almost surely, 2^213581124561 is an apocalyptic number.

213581124561 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

213581124561 is a deficient number, since it is larger than the sum of its proper divisors (137360929839).

213581124561 is a wasteful number, since it uses less digits than its factorization.

213581124561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13055949.

The product of its digits is 57600, while the sum is 39.

The spelling of 213581124561 in words is "two hundred thirteen billion, five hundred eighty-one million, one hundred twenty-four thousand, five hundred sixty-one".