340432781 has 4 divisors (see below), whose sum is σ = 366619932. Its totient is φ = 314245632.

The previous prime is 340432777. The next prime is 340432783. The reversal of 340432781 is 187234043.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 187234043 = 1021 ⋅183383.

It can be written as a sum of positive squares in 2 ways, for example, as 88924900 + 251507881 = 9430^2 + 15859^2 .

It is a cyclic number.

It is not a de Polignac number, because 340432781 - 2² = 340432777 is a prime.

It is a super-2 number, since 2×340432781² = 231788956758787922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (340432783) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13093556 + ... + 13093581.

It is an arithmetic number, because the mean of its divisors is an integer number (91654983).

Almost surely, 2^340432781 is an apocalyptic number.

It is an amenable number.

340432781 is a deficient number, since it is larger than the sum of its proper divisors (26187151).

340432781 is a wasteful number, since it uses less digits than its factorization.

340432781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26187150.

The product of its (nonzero) digits is 16128, while the sum is 32.

The square root of 340432781 is about 18450.8206050571. The cubic root of 340432781 is about 698.2492172531.

The spelling of 340432781 in words is "three hundred forty million, four hundred thirty-two thousand, seven hundred eighty-one".