340400021 has 8 divisors (see below), whose sum is σ = 368921784. Its totient is φ = 312212160.

The previous prime is 340400017. The next prime is 340400051. The reversal of 340400021 is 120004043.

It can be written as a sum of positive squares in 4 ways, for example, as 5692996 + 334707025 = 2386^2 + 18295^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 340400021 - 2² = 340400017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 340399969 and 340400005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (340400051) 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 7 ways as a sum of consecutive naturals, for example, 81350 + ... + 85431.

It is an arithmetic number, because the mean of its divisors is an integer number (46115223).

Almost surely, 2^340400021 is an apocalyptic number.

It is an amenable number.

340400021 is a deficient number, since it is larger than the sum of its proper divisors (28521763).

340400021 is a wasteful number, since it uses less digits than its factorization.

340400021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166951.

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 340400021 is about 18449.9328183059. The cubic root of 340400021 is about 698.2268189223.

Adding to 340400021 its reverse (120004043), we get a palindrome (460404064).

The spelling of 340400021 in words is "three hundred forty million, four hundred thousand, twenty-one".