681270049 has 2 divisors, whose sum is σ = 681270050. Its totient is φ = 681270048.

The previous prime is 681270047. The next prime is 681270067. The reversal of 681270049 is 940072186.

681270049 = T₂₁₃₁₀ + T₂₁₃₁₁ + T₂₁₃₁₂.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 352500625 + 328769424 = 18775^2 + 18132^2 .

It is a cyclic number.

It is not a de Polignac number, because 681270049 - 2¹ = 681270047 is a prime.

Together with 681270047, it forms a pair of twin primes.

It is equal to p_35332399 and since 681270049 and 35332399 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (681270047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340635024 + 340635025.

It is an arithmetic number, because the mean of its divisors is an integer number (340635025).

Almost surely, 2^681270049 is an apocalyptic number.

681270049 is the 21312-nd centered triangular number.

It is an amenable number.

681270049 is a deficient number, since it is larger than the sum of its proper divisors (1).

681270049 is an equidigital number, since it uses as much as digits as its factorization.

681270049 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 681270049 is about 26101.1503386345. The cubic root of 681270049 is about 879.9130634675.

The spelling of 681270049 in words is "six hundred eighty-one million, two hundred seventy thousand, forty-nine".