11501621221 has 2 divisors, whose sum is σ = 11501621222. Its totient is φ = 11501621220.

The previous prime is 11501621203. The next prime is 11501621231. The reversal of 11501621221 is 12212610511.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11195756100 + 305865121 = 105810^2 + 17489^2 .

It is a cyclic number.

It is not a de Polignac number, because 11501621221 - 2⁵ = 11501621189 is a prime.

It is a super-2 number, since 2×11501621221² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 11501621192 and 11501621201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11501621231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5750810610 + 5750810611.

It is an arithmetic number, because the mean of its divisors is an integer number (5750810611).

Almost surely, 2^11501621221 is an apocalyptic number.

It is an amenable number.

11501621221 is a deficient number, since it is larger than the sum of its proper divisors (1).

11501621221 is an equidigital number, since it uses as much as digits as its factorization.

11501621221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 240, while the sum is 22.

The spelling of 11501621221 in words is "eleven billion, five hundred one million, six hundred twenty-one thousand, two hundred twenty-one".