1921550357 has 2 divisors, whose sum is σ = 1921550358. Its totient is φ = 1921550356.

The previous prime is 1921550287. The next prime is 1921550369. The reversal of 1921550357 is 7530551291.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1873677796 + 47872561 = 43286^2 + 6919^2 .

It is an emirp because it is prime and its reverse (7530551291) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1921550357 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1921550357.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1921552357) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 960775178 + 960775179.

It is an arithmetic number, because the mean of its divisors is an integer number (960775179).

Almost surely, 2^1921550357 is an apocalyptic number.

It is an amenable number.

1921550357 is a deficient number, since it is larger than the sum of its proper divisors (1).

1921550357 is an equidigital number, since it uses as much as digits as its factorization.

1921550357 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 47250, while the sum is 38.

The square root of 1921550357 is about 43835.4919785326. The cubic root of 1921550357 is about 1243.2274484664.

The spelling of 1921550357 in words is "one billion, nine hundred twenty-one million, five hundred fifty thousand, three hundred fifty-seven".