220928381 has 2 divisors, whose sum is σ = 220928382. Its totient is φ = 220928380.

The previous prime is 220928353. The next prime is 220928387. The reversal of 220928381 is 183829022.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 127012900 + 93915481 = 11270^2 + 9691^2 .

It is a cyclic number.

It is not a de Polignac number, because 220928381 - 2²⁶ = 153819517 is a prime.

It is a super-2 number, since 2×220928381² = 97618699062562322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (220928387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110464190 + 110464191.

It is an arithmetic number, because the mean of its divisors is an integer number (110464191).

Almost surely, 2^220928381 is an apocalyptic number.

It is an amenable number.

220928381 is a deficient number, since it is larger than the sum of its proper divisors (1).

220928381 is an equidigital number, since it uses as much as digits as its factorization.

220928381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 220928381 is about 14863.6597444909. The cubic root of 220928381 is about 604.5290426756.

The spelling of 220928381 in words is "two hundred twenty million, nine hundred twenty-eight thousand, three hundred eighty-one".