351132721 has 2 divisors, whose sum is σ = 351132722. Its totient is φ = 351132720.

The previous prime is 351132713. The next prime is 351132779. The reversal of 351132721 is 127231153.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 351000225 + 132496 = 18735^2 + 364^2 .

It is a cyclic number.

It is not a de Polignac number, because 351132721 - 2³ = 351132713 is a prime.

It is not a weakly prime, because it can be changed into another prime (351132121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 175566360 + 175566361.

It is an arithmetic number, because the mean of its divisors is an integer number (175566361).

Almost surely, 2^351132721 is an apocalyptic number.

It is an amenable number.

351132721 is a deficient number, since it is larger than the sum of its proper divisors (1).

351132721 is an equidigital number, since it uses as much as digits as its factorization.

351132721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1260, while the sum is 25.

The square root of 351132721 is about 18738.5357218754. The cubic root of 351132721 is about 705.4893043691.

Adding to 351132721 its reverse (127231153), we get a palindrome (478363874).

The spelling of 351132721 in words is "three hundred fifty-one million, one hundred thirty-two thousand, seven hundred twenty-one".