1620432251 has 2 divisors, whose sum is σ = 1620432252. Its totient is φ = 1620432250.

The previous prime is 1620432241. The next prime is 1620432257. The reversal of 1620432251 is 1522340261.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1620432251 - 2¹⁸ = 1620170107 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1620432251.

It is not a weakly prime, because it can be changed into another prime (1620432257) 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 as a sum of consecutive naturals, namely, 810216125 + 810216126.

It is an arithmetic number, because the mean of its divisors is an integer number (810216126).

Almost surely, 2^1620432251 is an apocalyptic number.

1620432251 is a deficient number, since it is larger than the sum of its proper divisors (1).

1620432251 is an equidigital number, since it uses as much as digits as its factorization.

1620432251 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 1620432251 is about 40254.5929180758. The cubic root of 1620432251 is about 1174.5647401883.

The spelling of 1620432251 in words is "one billion, six hundred twenty million, four hundred thirty-two thousand, two hundred fifty-one".