1978000631 has 2 divisors, whose sum is σ = 1978000632. Its totient is φ = 1978000630.

The previous prime is 1978000613. The next prime is 1978000691. The reversal of 1978000631 is 1360008791.

Together with previous prime (1978000613) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1978000631 - 2¹⁴ = 1977984247 is a prime.

It is a super-2 number, since 2×1978000631² = 7824972992472796322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1978000591 and 1978000600.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1978000691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 989000315 + 989000316.

It is an arithmetic number, because the mean of its divisors is an integer number (989000316).

Almost surely, 2^1978000631 is an apocalyptic number.

1978000631 is a deficient number, since it is larger than the sum of its proper divisors (1).

1978000631 is an equidigital number, since it uses as much as digits as its factorization.

1978000631 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 35.

The square root of 1978000631 is about 44474.7190097925. The cubic root of 1978000631 is about 1255.2844296414.

The spelling of 1978000631 in words is "one billion, nine hundred seventy-eight million, six hundred thirty-one", and thus it is an aban number.