1978236427 has 2 divisors, whose sum is σ = 1978236428. Its totient is φ = 1978236426.

The previous prime is 1978236389. The next prime is 1978236473. The reversal of 1978236427 is 7246328791.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1978236427 is a prime.

It is a super-2 number, since 2×1978236427² = 7826838722219452658, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1975236427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 989118213 + 989118214.

It is an arithmetic number, because the mean of its divisors is an integer number (989118214).

Almost surely, 2^1978236427 is an apocalyptic number.

1978236427 is a deficient number, since it is larger than the sum of its proper divisors (1).

1978236427 is an equidigital number, since it uses as much as digits as its factorization.

1978236427 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1016064, while the sum is 49.

The square root of 1978236427 is about 44477.3698300608. The cubic root of 1978236427 is about 1255.3343081705.

The spelling of 1978236427 in words is "one billion, nine hundred seventy-eight million, two hundred thirty-six thousand, four hundred twenty-seven".