340981721 has 4 divisors (see below), whose sum is σ = 341533200. Its totient is φ = 340430244.

The previous prime is 340981717. The next prime is 340981723. The reversal of 340981721 is 127189043.

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: 127189043 = 257 ⋅494899.

It is a cyclic number.

It is not a de Polignac number, because 340981721 - 2² = 340981717 is a prime.

It is a super-2 number, since 2×340981721² = 232537068112243682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (340981723) 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 in 3 ways as a sum of consecutive naturals, for example, 274811 + ... + 276048.

It is an arithmetic number, because the mean of its divisors is an integer number (85383300).

Almost surely, 2^340981721 is an apocalyptic number.

It is an amenable number.

340981721 is a deficient number, since it is larger than the sum of its proper divisors (551479).

340981721 is an equidigital number, since it uses as much as digits as its factorization.

340981721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 551478.

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 340981721 is about 18465.6903743131. The cubic root of 340981721 is about 698.6243192918.

The spelling of 340981721 in words is "three hundred forty million, nine hundred eighty-one thousand, seven hundred twenty-one".