1621922849 has 2 divisors, whose sum is σ = 1621922850. Its totient is φ = 1621922848.

The previous prime is 1621922843. The next prime is 1621922881. The reversal of 1621922849 is 9482291261.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1583482849 + 38440000 = 39793^2 + 6200^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1621922849 is a prime.

It is not a weakly prime, because it can be changed into another prime (1621922843) 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, 810961424 + 810961425.

It is an arithmetic number, because the mean of its divisors is an integer number (810961425).

Almost surely, 2^1621922849 is an apocalyptic number.

It is an amenable number.

1621922849 is a deficient number, since it is larger than the sum of its proper divisors (1).

1621922849 is an equidigital number, since it uses as much as digits as its factorization.

1621922849 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 124416, while the sum is 44.

The square root of 1621922849 is about 40273.1032948791. The cubic root of 1621922849 is about 1174.9247814230.

The spelling of 1621922849 in words is "one billion, six hundred twenty-one million, nine hundred twenty-two thousand, eight hundred forty-nine".