345623721 has 16 divisors (see below), whose sum is σ = 471879744. Its totient is φ = 224953344.

The previous prime is 345623713. The next prime is 345623731. The reversal of 345623721 is 127326543.

It is not a de Polignac number, because 345623721 - 2³ = 345623713 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (345623731) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15105 + ... + 30321.

It is an arithmetic number, because the mean of its divisors is an integer number (29492484).

Almost surely, 2^345623721 is an apocalyptic number.

It is an amenable number.

345623721 is a deficient number, since it is larger than the sum of its proper divisors (126256023).

345623721 is a wasteful number, since it uses less digits than its factorization.

345623721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15400.

The product of its digits is 30240, while the sum is 33.

The square root of 345623721 is about 18590.9580441676. The cubic root of 345623721 is about 701.7803125039.

It can be divided in two parts, 34562 and 3721, that added together give a palindrome (38283).

The spelling of 345623721 in words is "three hundred forty-five million, six hundred twenty-three thousand, seven hundred twenty-one".