155749440 has 448 divisors, whose sum is σ = 643737600. Its totient is φ = 31610880.

The previous prime is 155749421. The next prime is 155749463. The reversal of 155749440 is 44947551.

It is a tau number, because it is divible by the number of its divisors (448).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3622059 + ... + 3622101.

Almost surely, 2^155749440 is an apocalyptic number.

155749440 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 155749440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (321868800).

155749440 is an abundant number, since it is smaller than the sum of its proper divisors (487988160).

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

155749440 is a wasteful number, since it uses less digits than its factorization.

155749440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 100800, while the sum is 39.

The square root of 155749440 is about 12479.9615384023. The cubic root of 155749440 is about 538.0328978469.

The spelling of 155749440 in words is "one hundred fifty-five million, seven hundred forty-nine thousand, four hundred forty".