221338091531 has 2 divisors, whose sum is σ = 221338091532. Its totient is φ = 221338091530.

The previous prime is 221338091473. The next prime is 221338091567. The reversal of 221338091531 is 135190833122.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221338091531 - 2¹⁸ = 221337829387 is a prime.

It is a super-2 number, since 2×221338091531² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (221338091581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110669045765 + 110669045766.

It is an arithmetic number, because the mean of its divisors is an integer number (110669045766).

Almost surely, 2^221338091531 is an apocalyptic number.

221338091531 is a deficient number, since it is larger than the sum of its proper divisors (1).

221338091531 is an equidigital number, since it uses as much as digits as its factorization.

221338091531 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 38880, while the sum is 38.

The spelling of 221338091531 in words is "two hundred twenty-one billion, three hundred thirty-eight million, ninety-one thousand, five hundred thirty-one".