1621170043 has 2 divisors, whose sum is σ = 1621170044. Its totient is φ = 1621170042.

The previous prime is 1621170011. The next prime is 1621170049. The reversal of 1621170043 is 3400711261.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1621170043 - 2⁵ = 1621170011 is a prime.

It is not a weakly prime, because it can be changed into another prime (1621170049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810585021 + 810585022.

It is an arithmetic number, because the mean of its divisors is an integer number (810585022).

Almost surely, 2^1621170043 is an apocalyptic number.

1621170043 is a deficient number, since it is larger than the sum of its proper divisors (1).

1621170043 is an equidigital number, since it uses as much as digits as its factorization.

1621170043 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 1621170043 is about 40263.7559475020. The cubic root of 1621170043 is about 1174.7429751379.

The spelling of 1621170043 in words is "one billion, six hundred twenty-one million, one hundred seventy thousand, forty-three".