1629122221 has 2 divisors, whose sum is σ = 1629122222. Its totient is φ = 1629122220.

The previous prime is 1629122213. The next prime is 1629122227. The reversal of 1629122221 is 1222219261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1442936196 + 186186025 = 37986^2 + 13645^2 .

It is a cyclic number.

It is not a de Polignac number, because 1629122221 - 2³ = 1629122213 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1629122221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1629122227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 814561110 + 814561111.

It is an arithmetic number, because the mean of its divisors is an integer number (814561111).

Almost surely, 2^1629122221 is an apocalyptic number.

It is an amenable number.

1629122221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1629122221 is an equidigital number, since it uses as much as digits as its factorization.

1629122221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1728, while the sum is 28.

The square root of 1629122221 is about 40362.3862153862. The cubic root of 1629122221 is about 1176.6606296810.

The spelling of 1629122221 in words is "one billion, six hundred twenty-nine million, one hundred twenty-two thousand, two hundred twenty-one".