155531394 has 32 divisors (see below), whose sum is σ = 346213440. Its totient is φ = 51755616.

The previous prime is 155531381. The next prime is 155531407. The reversal of 155531394 is 493135551.

It is a happy number.

155531394 is a `hidden beast` number, since 1 + 5 + 553 + 13 + 94 = 666.

It is an interprime number because it is at equal distance from previous prime (155531381) and next prime (155531407).

It is a super-3 number, since 3×155531394³ (a number of 26 digits) contains 333 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34774 + ... + 38990.

It is an arithmetic number, because the mean of its divisors is an integer number (10819170).

Almost surely, 2^155531394 is an apocalyptic number.

155531394 is an abundant number, since it is smaller than the sum of its proper divisors (190682046).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

155531394 is a wasteful number, since it uses less digits than its factorization.

155531394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4911 (or 4905 counting only the distinct ones).

The product of its digits is 40500, while the sum is 36.

The square root of 155531394 is about 12471.2226345295. Note that the first 3 decimals coincide. The cubic root of 155531394 is about 537.7817022717.

The spelling of 155531394 in words is "one hundred fifty-five million, five hundred thirty-one thousand, three hundred ninety-four".