345645131621 has 4 divisors (see below), whose sum is σ = 352166737932. Its totient is φ = 339123525312.

The previous prime is 345645131603. The next prime is 345645131633. The reversal of 345645131621 is 126131546543.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 126131546543 = 113111 ⋅1115113.

It can be written as a sum of positive squares in 2 ways, for example, as 281679640225 + 63965491396 = 530735^2 + 252914^2 .

It is a cyclic number.

It is not a de Polignac number, because 345645131621 - 2³⁸ = 70767224677 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 (345645131521) 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, 3260803076 + ... + 3260803181.

It is an arithmetic number, because the mean of its divisors is an integer number (88041684483).

Almost surely, 2^345645131621 is an apocalyptic number.

It is an amenable number.

345645131621 is a deficient number, since it is larger than the sum of its proper divisors (6521606311).

345645131621 is an equidigital number, since it uses as much as digits as its factorization.

345645131621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6521606310.

The product of its digits is 259200, while the sum is 41.

The spelling of 345645131621 in words is "three hundred forty-five billion, six hundred forty-five million, one hundred thirty-one thousand, six hundred twenty-one".