1620742393 has 2 divisors, whose sum is σ = 1620742394. Its totient is φ = 1620742392.

The previous prime is 1620742327. The next prime is 1620742429. The reversal of 1620742393 is 3932470261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1619901504 + 840889 = 40248^2 + 917^2 .

It is a cyclic number.

It is not a de Polignac number, because 1620742393 - 2¹³ = 1620734201 is a prime.

It is not a weakly prime, because it can be changed into another prime (1620742993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810371196 + 810371197.

It is an arithmetic number, because the mean of its divisors is an integer number (810371197).

Almost surely, 2^1620742393 is an apocalyptic number.

It is an amenable number.

1620742393 is a deficient number, since it is larger than the sum of its proper divisors (1).

1620742393 is an equidigital number, since it uses as much as digits as its factorization.

1620742393 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54432, while the sum is 37.

The square root of 1620742393 is about 40258.4449898403. Note that the first 3 decimals coincide. The cubic root of 1620742393 is about 1174.6396705285.

The spelling of 1620742393 in words is "one billion, six hundred twenty million, seven hundred forty-two thousand, three hundred ninety-three".