21550320131 has 8 divisors (see below), whose sum is σ = 21753217200. Its totient is φ = 21347517600.

The previous prime is 21550320109. The next prime is 21550320217. The reversal of 21550320131 is 13102305512.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21550320131 - 2⁶ = 21550320067 is a prime.

It is a super-2 number, since 2×21550320131² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21550320097 and 21550320106.

It is not an unprimeable number, because it can be changed into a prime (21550320331) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 485705 + ... + 528213.

It is an arithmetic number, because the mean of its divisors is an integer number (2719152150).

Almost surely, 2^21550320131 is an apocalyptic number.

21550320131 is a deficient number, since it is larger than the sum of its proper divisors (202897069).

21550320131 is a wasteful number, since it uses less digits than its factorization.

21550320131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47269.

The product of its (nonzero) digits is 900, while the sum is 23.

Adding to 21550320131 its reverse (13102305512), we get a palindrome (34652625643).

The spelling of 21550320131 in words is "twenty-one billion, five hundred fifty million, three hundred twenty thousand, one hundred thirty-one".