1256121983 has 2 divisors, whose sum is σ = 1256121984. Its totient is φ = 1256121982.

The previous prime is 1256121949. The next prime is 1256122003. The reversal of 1256121983 is 3891216521.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1256121983 - 2¹² = 1256117887 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1256121913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 628060991 + 628060992.

It is an arithmetic number, because the mean of its divisors is an integer number (628060992).

Almost surely, 2^1256121983 is an apocalyptic number.

1256121983 is a deficient number, since it is larger than the sum of its proper divisors (1).

1256121983 is an equidigital number, since it uses as much as digits as its factorization.

1256121983 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 38.

The square root of 1256121983 is about 35441.8112262903. The cubic root of 1256121983 is about 1078.9730701955.

The spelling of 1256121983 in words is "one billion, two hundred fifty-six million, one hundred twenty-one thousand, nine hundred eighty-three".