1138156021 has 2 divisors, whose sum is σ = 1138156022. Its totient is φ = 1138156020.

The previous prime is 1138156013. The next prime is 1138156027. The reversal of 1138156021 is 1206518311.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 975312900 + 162843121 = 31230^2 + 12761^2 .

It is a cyclic number.

It is not a de Polignac number, because 1138156021 - 2³ = 1138156013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1138156027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 569078010 + 569078011.

It is an arithmetic number, because the mean of its divisors is an integer number (569078011).

Almost surely, 2^1138156021 is an apocalyptic number.

It is an amenable number.

1138156021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1138156021 is an equidigital number, since it uses as much as digits as its factorization.

1138156021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 1138156021 is about 33736.5680086164. The cubic root of 1138156021 is about 1044.0803768189.

The spelling of 1138156021 in words is "one billion, one hundred thirty-eight million, one hundred fifty-six thousand, twenty-one".