345220521 has 4 divisors (see below), whose sum is σ = 460294032. Its totient is φ = 230147012.

The previous prime is 345220517. The next prime is 345220541. The reversal of 345220521 is 125022543.

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.

It is a cyclic number.

It is not a de Polignac number, because 345220521 - 2² = 345220517 is a prime.

It is a super-2 number, since 2×345220521² = 238354416239022882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 345220491 and 345220500.

It is not an unprimeable number, because it can be changed into a prime (345220541) 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, 57536751 + ... + 57536756.

It is an arithmetic number, because the mean of its divisors is an integer number (115073508).

Almost surely, 2^345220521 is an apocalyptic number.

It is an amenable number.

345220521 is a deficient number, since it is larger than the sum of its proper divisors (115073511).

345220521 is a wasteful number, since it uses less digits than its factorization.

345220521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115073510.

The product of its (nonzero) digits is 2400, while the sum is 24.

The square root of 345220521 is about 18580.1108984850. The cubic root of 345220521 is about 701.5073104811.

The spelling of 345220521 in words is "three hundred forty-five million, two hundred twenty thousand, five hundred twenty-one".