221121513 has 12 divisors (see below), whose sum is σ = 321543300. Its totient is φ = 146424096.

The previous prime is 221121493. The next prime is 221121521. The reversal of 221121513 is 315121122.

It can be written as a sum of positive squares in 2 ways, for example, as 49956624 + 171164889 = 7068^2 + 13083^2 .

It is not a de Polignac number, because 221121513 - 2¹⁶ = 221055977 is a prime.

It is a super-2 number, since 2×221121513² = 97789447022818338, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (221121013) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 81106 + ... + 83787.

It is an arithmetic number, because the mean of its divisors is an integer number (26795275).

Almost surely, 2^221121513 is an apocalyptic number.

It is an amenable number.

221121513 is a deficient number, since it is larger than the sum of its proper divisors (100421787).

221121513 is a wasteful number, since it uses less digits than its factorization.

221121513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165048 (or 165045 counting only the distinct ones).

The product of its digits is 120, while the sum is 18.

The square root of 221121513 is about 14870.1551101527. The cubic root of 221121513 is about 604.7051478574.

Adding to 221121513 its reverse (315121122), we get a palindrome (536242635).

The spelling of 221121513 in words is "two hundred twenty-one million, one hundred twenty-one thousand, five hundred thirteen".