345881821 has 4 divisors (see below), whose sum is σ = 346639132. Its totient is φ = 345124512.

The previous prime is 345881819. The next prime is 345881831. The reversal of 345881821 is 128188543.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 260984025 + 84897796 = 16155^2 + 9214^2 .

It is a cyclic number.

It is not a de Polignac number, because 345881821 - 2¹ = 345881819 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (345881801) 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, 377970 + ... + 378883.

It is an arithmetic number, because the mean of its divisors is an integer number (86659783).

Almost surely, 2^345881821 is an apocalyptic number.

It is an amenable number.

345881821 is a deficient number, since it is larger than the sum of its proper divisors (757311).

345881821 is an equidigital number, since it uses as much as digits as its factorization.

345881821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 757310.

The product of its digits is 61440, while the sum is 40.

The square root of 345881821 is about 18597.8982952376. The cubic root of 345881821 is about 701.9549575676.

The spelling of 345881821 in words is "three hundred forty-five million, eight hundred eighty-one thousand, eight hundred twenty-one".