628133021 has 2 divisors, whose sum is σ = 628133022. Its totient is φ = 628133020.

The previous prime is 628132991. The next prime is 628133041. The reversal of 628133021 is 120331826.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 620707396 + 7425625 = 24914^2 + 2725^2 .

It is a cyclic number.

It is not a de Polignac number, because 628133021 - 2²² = 623938717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (628133041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 314066510 + 314066511.

It is an arithmetic number, because the mean of its divisors is an integer number (314066511).

Almost surely, 2^628133021 is an apocalyptic number.

It is an amenable number.

628133021 is a deficient number, since it is larger than the sum of its proper divisors (1).

628133021 is an equidigital number, since it uses as much as digits as its factorization.

628133021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 628133021 is about 25062.5820896411. The cubic root of 628133021 is about 856.4142302704.

Adding to 628133021 its reverse (120331826), we get a palindrome (748464847).

The spelling of 628133021 in words is "six hundred twenty-eight million, one hundred thirty-three thousand, twenty-one".