681401947 has 2 divisors, whose sum is σ = 681401948. Its totient is φ = 681401946.

The previous prime is 681401899. The next prime is 681401957. The reversal of 681401947 is 749104186.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-681401947 is a prime.

It is a super-2 number, since 2×681401947² = 928617226750781618, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (681401957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340700973 + 340700974.

It is an arithmetic number, because the mean of its divisors is an integer number (340700974).

Almost surely, 2^681401947 is an apocalyptic number.

681401947 is a deficient number, since it is larger than the sum of its proper divisors (1).

681401947 is an equidigital number, since it uses as much as digits as its factorization.

681401947 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48384, while the sum is 40.

The square root of 681401947 is about 26103.6768865997. The cubic root of 681401947 is about 879.9698452994.

The spelling of 681401947 in words is "six hundred eighty-one million, four hundred one thousand, nine hundred forty-seven".