155006993 has 2 divisors, whose sum is σ = 155006994. Its totient is φ = 155006992.

The previous prime is 155006963. The next prime is 155007007. The reversal of 155006993 is 399600551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 154952704 + 54289 = 12448^2 + 233^2 .

It is a cyclic number.

It is not a de Polignac number, because 155006993 - 2¹⁰ = 155005969 is a prime.

155006993 is a modest number, since divided by 6993 gives 155 as remainder.

It is not a weakly prime, because it can be changed into another prime (155006903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77503496 + 77503497.

It is an arithmetic number, because the mean of its divisors is an integer number (77503497).

Almost surely, 2^155006993 is an apocalyptic number.

It is an amenable number.

155006993 is a deficient number, since it is larger than the sum of its proper divisors (1).

155006993 is an equidigital number, since it uses as much as digits as its factorization.

155006993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36450, while the sum is 38.

The square root of 155006993 is about 12450.1804404595. The cubic root of 155006993 is about 537.1766136947.

The spelling of 155006993 in words is "one hundred fifty-five million, six thousand, nine hundred ninety-three".