21200631031541 has 4 divisors (see below), whose sum is σ = 22831448803212. Its totient is φ = 19569813259872.

The previous prime is 21200631031469. The next prime is 21200631031583. The reversal of 21200631031541 is 14513013600212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1760212492900 + 19440418538641 = 1326730^2 + 4409129^2 .

It is a cyclic number.

It is not a de Polignac number, because 21200631031541 - 2²² = 21200626837237 is a prime.

It is a super-2 number, since 2×21200631031541² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200631031441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 815408885816 + ... + 815408885841.

It is an arithmetic number, because the mean of its divisors is an integer number (5707862200803).

Almost surely, 2^{21200631031541} is an apocalyptic number.

It is an amenable number.

21200631031541 is a deficient number, since it is larger than the sum of its proper divisors (1630817771671).

21200631031541 is a wasteful number, since it uses less digits than its factorization.

21200631031541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1630817771670.

The product of its (nonzero) digits is 4320, while the sum is 29.

Adding to 21200631031541 its reverse (14513013600212), we get a palindrome (35713644631753).

The spelling of 21200631031541 in words is "twenty-one trillion, two hundred billion, six hundred thirty-one million, thirty-one thousand, five hundred forty-one".