340556561 has 4 divisors (see below), whose sum is σ = 355363392. Its totient is φ = 325749732.

The previous prime is 340556527. The next prime is 340556633. The reversal of 340556561 is 165655043.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 165655043 = 1039 ⋅159437.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-340556561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (340556521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7403381 + ... + 7403426.

It is an arithmetic number, because the mean of its divisors is an integer number (88840848).

Almost surely, 2^340556561 is an apocalyptic number.

It is an amenable number.

340556561 is a deficient number, since it is larger than the sum of its proper divisors (14806831).

340556561 is a wasteful number, since it uses less digits than its factorization.

340556561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14806830.

The product of its (nonzero) digits is 54000, while the sum is 35.

The square root of 340556561 is about 18454.1746225617. The cubic root of 340556561 is about 698.3338338744. Note that the first 3 decimals are identical.

The spelling of 340556561 in words is "three hundred forty million, five hundred fifty-six thousand, five hundred sixty-one".