155197440 has 168 divisors, whose sum is σ = 539262828. Its totient is φ = 41287680.

The previous prime is 155197411. The next prime is 155197447. The reversal of 155197440 is 44791551.

It can be written as a sum of positive squares in 2 ways, for example, as 128323584 + 26873856 = 11328^2 + 5184^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 155197395 and 155197404.

It is not an unprimeable number, because it can be changed into a prime (155197447) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 368430 + ... + 368850.

Almost surely, 2^155197440 is an apocalyptic number.

155197440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 155197440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (269631414).

155197440 is an abundant number, since it is smaller than the sum of its proper divisors (384065388).

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

155197440 is an equidigital number, since it uses as much as digits as its factorization.

155197440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 458 (or 431 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 36.

The square root of 155197440 is about 12457.8264556864. The cubic root of 155197440 is about 537.3965216338.

The spelling of 155197440 in words is "one hundred fifty-five million, one hundred ninety-seven thousand, four hundred forty".