211561434525 has 48 divisors (see below), whose sum is σ = 399799732608. Its totient is φ = 96701856000.

The previous prime is 211561434463. The next prime is 211561434529. The reversal of 211561434525 is 525434165112.

It is not a de Polignac number, because 211561434525 - 2⁹ = 211561434013 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211561434529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5325235 + ... + 5364815.

It is an arithmetic number, because the mean of its divisors is an integer number (8329161096).

Almost surely, 2^211561434525 is an apocalyptic number.

211561434525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

211561434525 is a deficient number, since it is larger than the sum of its proper divisors (188238298083).

211561434525 is a wasteful number, since it uses less digits than its factorization.

211561434525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49782 (or 49777 counting only the distinct ones).

The product of its digits is 144000, while the sum is 39.

Adding to 211561434525 its reverse (525434165112), we get a palindrome (736995599637).

The spelling of 211561434525 in words is "two hundred eleven billion, five hundred sixty-one million, four hundred thirty-four thousand, five hundred twenty-five".