1231780211 has 2 divisors, whose sum is σ = 1231780212. Its totient is φ = 1231780210.

The previous prime is 1231780189. The next prime is 1231780217. The reversal of 1231780211 is 1120871321.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1231780211 - 2¹⁰ = 1231779187 is a prime.

It is a super-2 number, since 2×1231780211² = 3034564976422409042, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1231780217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615890105 + 615890106.

It is an arithmetic number, because the mean of its divisors is an integer number (615890106).

Almost surely, 2^1231780211 is an apocalyptic number.

1231780211 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231780211 is an equidigital number, since it uses as much as digits as its factorization.

1231780211 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 672, while the sum is 26.

The square root of 1231780211 is about 35096.7264997749. The cubic root of 1231780211 is about 1071.9579287877.

The spelling of 1231780211 in words is "one billion, two hundred thirty-one million, seven hundred eighty thousand, two hundred eleven".