1621130243 has 2 divisors, whose sum is σ = 1621130244. Its totient is φ = 1621130242.

The previous prime is 1621130237. The next prime is 1621130279. The reversal of 1621130243 is 3420311261.

It is a weak prime.

It is an emirp because it is prime and its reverse (3420311261) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1621130243 is a prime.

It is not a weakly prime, because it can be changed into another prime (1621190243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810565121 + 810565122.

It is an arithmetic number, because the mean of its divisors is an integer number (810565122).

Almost surely, 2^1621130243 is an apocalyptic number.

1621130243 is a deficient number, since it is larger than the sum of its proper divisors (1).

1621130243 is an equidigital number, since it uses as much as digits as its factorization.

1621130243 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 1621130243 is about 40263.2617034437. The cubic root of 1621130243 is about 1174.7333616793.

The spelling of 1621130243 in words is "one billion, six hundred twenty-one million, one hundred thirty thousand, two hundred forty-three".