221413531 has 4 divisors (see below), whose sum is σ = 222693552. Its totient is φ = 220133512.

The previous prime is 221413529. The next prime is 221413541. The reversal of 221413531 is 135314122.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 135314122 = 2 ⋅67657061.

It is a cyclic number.

It is not a de Polignac number, because 221413531 - 2¹ = 221413529 is a prime.

It is a super-2 number, since 2×221413531² = 98047903419775922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221413541) 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, 639751 + ... + 640096.

It is an arithmetic number, because the mean of its divisors is an integer number (55673388).

Almost surely, 2^221413531 is an apocalyptic number.

221413531 is a deficient number, since it is larger than the sum of its proper divisors (1280021).

221413531 is a wasteful number, since it uses less digits than its factorization.

221413531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1280020.

The product of its digits is 720, while the sum is 22.

The square root of 221413531 is about 14879.9707997025. The cubic root of 221413531 is about 604.9712264621.

Adding to 221413531 its reverse (135314122), we get a palindrome (356727653).

The spelling of 221413531 in words is "two hundred twenty-one million, four hundred thirteen thousand, five hundred thirty-one".