155973121 has 8 divisors (see below), whose sum is σ = 161215488. Its totient is φ = 150744000.

The previous prime is 155973101. The next prime is 155973127. The reversal of 155973121 is 121379551.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 155973121 - 2²³ = 147584513 is a prime.

It is a super-2 number, since 2×155973121² = 48655228948961282, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155973127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24456 + ... + 30166.

It is an arithmetic number, because the mean of its divisors is an integer number (20151936).

Almost surely, 2^155973121 is an apocalyptic number.

It is an amenable number.

155973121 is a deficient number, since it is larger than the sum of its proper divisors (5242367).

155973121 is an equidigital number, since it uses as much as digits as its factorization.

155973121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6623.

The product of its digits is 9450, while the sum is 34.

The square root of 155973121 is about 12488.9199292813. The cubic root of 155973121 is about 538.2903416183.

It can be divided in two parts, 15 and 5973121, that added together give a square (5973136 = 2444²).

The spelling of 155973121 in words is "one hundred fifty-five million, nine hundred seventy-three thousand, one hundred twenty-one".