21133503100161 has 45 divisors (see below), whose sum is σ = 31681381659411. Its totient is φ = 14039380764288.

The previous prime is 21133503100117. The next prime is 21133503100163. The reversal of 21133503100161 is 16100130533112.

It is a happy number.

The square root of 21133503100161 is 4597119.

It is a perfect power (a square), and thus also a powerful number.

21133503100161 is a `hidden beast` number, since 2 + 1 + 1 + 335 + 0 + 310 + 0 + 16 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 8585925530625 + 12547577569536 = 2930175^2 + 3542256^2 .

It is not a de Polignac number, because 21133503100161 - 2²¹ = 21133501003009 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21133503100163) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 14605046340 + ... + 14605047786.

Almost surely, 2^{21133503100161} is an apocalyptic number.

21133503100161 is the 4597119-th square number.

21133503100161 is the 2298560-th centered octagonal number.

It is an amenable number.

21133503100161 is a deficient number, since it is larger than the sum of its proper divisors (10547878559250).

21133503100161 is an frugal number, since it uses more digits than its factorization.

21133503100161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3612 (or 1803 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

Adding to 21133503100161 its reverse (16100130533112), we get a palindrome (37233633633273).

It can be divided in two parts, 21133503 and 100161, that added together give a square (21233664 = 4608²).

The spelling of 21133503100161 in words is "twenty-one trillion, one hundred thirty-three billion, five hundred three million, one hundred thousand, one hundred sixty-one".