221151031 has 4 divisors (see below), whose sum is σ = 221205600. Its totient is φ = 221096464.

The previous prime is 221151019. The next prime is 221151037. The reversal of 221151031 is 130151122.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 130151122 = 2 ⋅65075561.

It is a cyclic number.

It is not a de Polignac number, because 221151031 - 2⁷ = 221150903 is a prime.

It is a super-2 number, since 2×221151031² = 97815557024725922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221150996 and 221151014.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221151037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20671 + ... + 29488.

It is an arithmetic number, because the mean of its divisors is an integer number (55301400).

Almost surely, 2^221151031 is an apocalyptic number.

221151031 is a deficient number, since it is larger than the sum of its proper divisors (54569).

221151031 is an equidigital number, since it uses as much as digits as its factorization.

221151031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54568.

The product of its (nonzero) digits is 60, while the sum is 16.

The square root of 221151031 is about 14871.1476019842. The cubic root of 221151031 is about 604.7320544696.

Subtracting from 221151031 its reverse (130151122), we obtain a palindrome (90999909).

The spelling of 221151031 in words is "two hundred twenty-one million, one hundred fifty-one thousand, thirty-one".