155406321 has 24 divisors (see below), whose sum is σ = 257449920. Its totient is φ = 88490016.

The previous prime is 155406313. The next prime is 155406323. The reversal of 155406321 is 123604551.

It is not a de Polignac number, because 155406321 - 2³ = 155406313 is a prime.

It is a super-2 number, since 2×155406321² = 48302249213510082, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (155406323) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14250 + ... + 22668.

It is an arithmetic number, because the mean of its divisors is an integer number (10727080).

Almost surely, 2^155406321 is an apocalyptic number.

It is an amenable number.

155406321 is a deficient number, since it is larger than the sum of its proper divisors (102043599).

155406321 is a wasteful number, since it uses less digits than its factorization.

155406321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8725 (or 8722 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 155406321 is about 12466.2071617634. The cubic root of 155406321 is about 537.6375084274.

The spelling of 155406321 in words is "one hundred fifty-five million, four hundred six thousand, three hundred twenty-one".