155997901 has 2 divisors, whose sum is σ = 155997902. Its totient is φ = 155997900.

The previous prime is 155997889. The next prime is 155997943. The reversal of 155997901 is 109799551.

155997901 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 141633801 + 14364100 = 11901^2 + 3790^2 .

It is a cyclic number.

It is not a de Polignac number, because 155997901 - 2¹³ = 155989709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155997971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77998950 + 77998951.

It is an arithmetic number, because the mean of its divisors is an integer number (77998951).

Almost surely, 2^155997901 is an apocalyptic number.

It is an amenable number.

155997901 is a deficient number, since it is larger than the sum of its proper divisors (1).

155997901 is an equidigital number, since it uses as much as digits as its factorization.

155997901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 127575, while the sum is 46.

The square root of 155997901 is about 12489.9119692654. The cubic root of 155997901 is about 538.3188468040.

It can be divided in two parts, 15 and 5997901, that added together give a triangular number (5997916 = T₃₄₆₃).

The spelling of 155997901 in words is "one hundred fifty-five million, nine hundred ninety-seven thousand, nine hundred one".