351420021 has 6 divisors (see below), whose sum is σ = 507606710. Its totient is φ = 234280008.

The previous prime is 351420011. The next prime is 351420031. The reversal of 351420021 is 120024153.

It is an interprime number because it is at equal distance from previous prime (351420011) and next prime (351420031).

It can be written as a sum of positive squares in only one way, i.e., 346518225 + 4901796 = 18615^2 + 2214^2 .

It is not a de Polignac number, because 351420021 - 2¹⁹ = 350895733 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 351419976 and 351420003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (351420011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 19523326 + ... + 19523343.

Almost surely, 2^351420021 is an apocalyptic number.

It is an amenable number.

351420021 is a deficient number, since it is larger than the sum of its proper divisors (156186689).

351420021 is a wasteful number, since it uses less digits than its factorization.

351420021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39046675 (or 39046672 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 351420021 is about 18746.2001749688. The cubic root of 351420021 is about 705.6816645129.

Adding to 351420021 its reverse (120024153), we get a palindrome (471444174).

The spelling of 351420021 in words is "three hundred fifty-one million, four hundred twenty thousand, twenty-one".