191220949 has 2 divisors, whose sum is σ = 191220950. Its totient is φ = 191220948.

The previous prime is 191220929. The next prime is 191221033. The reversal of 191220949 is 949022191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 162384049 + 28836900 = 12743^2 + 5370^2 .

It is a cyclic number.

It is not a de Polignac number, because 191220949 - 2¹³ = 191212757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191220929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95610474 + 95610475.

It is an arithmetic number, because the mean of its divisors is an integer number (95610475).

Almost surely, 2^191220949 is an apocalyptic number.

It is an amenable number.

191220949 is a deficient number, since it is larger than the sum of its proper divisors (1).

191220949 is an equidigital number, since it uses as much as digits as its factorization.

191220949 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 37.

The square root of 191220949 is about 13828.2663049277. The cubic root of 191220949 is about 576.1185023755.

The spelling of 191220949 in words is "one hundred ninety-one million, two hundred twenty thousand, nine hundred forty-nine".