155772005 has 4 divisors (see below), whose sum is σ = 186926412. Its totient is φ = 124617600.

The previous prime is 155771989. The next prime is 155772011. The reversal of 155772005 is 500277551.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 500277551 = 2729 ⋅183319.

It can be written as a sum of positive squares in 2 ways, for example, as 100982401 + 54789604 = 10049^2 + 7402^2 .

It is not a de Polignac number, because 155772005 - 2⁴ = 155771989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15577196 + ... + 15577205.

It is an arithmetic number, because the mean of its divisors is an integer number (46731603).

Almost surely, 2^155772005 is an apocalyptic number.

It is an amenable number.

155772005 is a deficient number, since it is larger than the sum of its proper divisors (31154407).

155772005 is an equidigital number, since it uses as much as digits as its factorization.

155772005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31154406.

The product of its (nonzero) digits is 12250, while the sum is 32.

The square root of 155772005 is about 12480.8655549205. The cubic root of 155772005 is about 538.0588800186.

The spelling of 155772005 in words is "one hundred fifty-five million, seven hundred seventy-two thousand, five".