620155993 has 2 divisors, whose sum is σ = 620155994. Its totient is φ = 620155992.

The previous prime is 620155979. The next prime is 620156051. The reversal of 620155993 is 399551026.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 568488649 + 51667344 = 23843^2 + 7188^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-620155993 is a prime.

It is not a weakly prime, because it can be changed into another prime (620155793) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310077996 + 310077997.

It is an arithmetic number, because the mean of its divisors is an integer number (310077997).

Almost surely, 2^620155993 is an apocalyptic number.

It is an amenable number.

620155993 is a deficient number, since it is larger than the sum of its proper divisors (1).

620155993 is an equidigital number, since it uses as much as digits as its factorization.

620155993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72900, while the sum is 40.

The square root of 620155993 is about 24902.9314137914. The cubic root of 620155993 is about 852.7734060557.

The spelling of 620155993 in words is "six hundred twenty million, one hundred fifty-five thousand, nine hundred ninety-three".