2133997781 has 2 divisors, whose sum is σ = 2133997782. Its totient is φ = 2133997780.

The previous prime is 2133997759. The next prime is 2133997819. The reversal of 2133997781 is 1877993312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2069340100 + 64657681 = 45490^2 + 8041^2 .

It is a cyclic number.

It is not a de Polignac number, because 2133997781 - 2¹⁴ = 2133981397 is a prime.

It is a super-2 number, since 2×2133997781² = 9107893058625847922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2133997721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1066998890 + 1066998891.

It is an arithmetic number, because the mean of its divisors is an integer number (1066998891).

Almost surely, 2^2133997781 is an apocalyptic number.

It is an amenable number.

2133997781 is a deficient number, since it is larger than the sum of its proper divisors (1).

2133997781 is an equidigital number, since it uses as much as digits as its factorization.

2133997781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 571536, while the sum is 50.

The square root of 2133997781 is about 46195.2138321710. The cubic root of 2133997781 is about 1287.4528150113.

The spelling of 2133997781 in words is "two billion, one hundred thirty-three million, nine hundred ninety-seven thousand, seven hundred eighty-one".