1011881621 has 2 divisors, whose sum is σ = 1011881622. Its totient is φ = 1011881620.

The previous prime is 1011881569. The next prime is 1011881627. The reversal of 1011881621 is 1261881101.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 561168721 + 450712900 = 23689^2 + 21230^2 .

It is a cyclic number.

It is not a de Polignac number, because 1011881621 - 2²⁶ = 944772757 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1011881627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 505940810 + 505940811.

It is an arithmetic number, because the mean of its divisors is an integer number (505940811).

Almost surely, 2^1011881621 is an apocalyptic number.

It is an amenable number.

1011881621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1011881621 is an equidigital number, since it uses as much as digits as its factorization.

1011881621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768, while the sum is 29.

The square root of 1011881621 is about 31810.0867807681. The cubic root of 1011881621 is about 1003.9449571815.

The spelling of 1011881621 in words is "one billion, eleven million, eight hundred eighty-one thousand, six hundred twenty-one".