1899826561 has 2 divisors, whose sum is σ = 1899826562. Its totient is φ = 1899826560.

The previous prime is 1899826547. The next prime is 1899826571. The reversal of 1899826561 is 1656289981.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1793014336 + 106812225 = 42344^2 + 10335^2 .

It is a cyclic number.

It is not a de Polignac number, because 1899826561 - 2¹³ = 1899818369 is a prime.

It is not a weakly prime, because it can be changed into another prime (1899826501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 949913280 + 949913281.

It is an arithmetic number, because the mean of its divisors is an integer number (949913281).

Almost surely, 2^1899826561 is an apocalyptic number.

It is an amenable number.

1899826561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1899826561 is an equidigital number, since it uses as much as digits as its factorization.

1899826561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1866240, while the sum is 55.

The square root of 1899826561 is about 43586.9999082295. Note that the first 4 decimals coincide. The cubic root of 1899826561 is about 1238.5246416392.

The spelling of 1899826561 in words is "one billion, eight hundred ninety-nine million, eight hundred twenty-six thousand, five hundred sixty-one".