155421152440 has 64 divisors (see below), whose sum is σ = 354916080000. Its totient is φ = 61244252160.

The previous prime is 155421152437. The next prime is 155421152473. The reversal of 155421152440 is 44251124551.

It is a junction number, because it is equal to n+sod(n) for n = 155421152396 and 155421152405.

It is a congruent 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, 1364070 + ... + 1473610.

It is an arithmetic number, because the mean of its divisors is an integer number (5545563750).

Almost surely, 2^155421152440 is an apocalyptic number.

155421152440 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 155421152440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (177458040000).

155421152440 is an abundant number, since it is smaller than the sum of its proper divisors (199494927560).

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

155421152440 is a wasteful number, since it uses less digits than its factorization.

155421152440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110080 (or 110076 counting only the distinct ones).

The product of its (nonzero) digits is 32000, while the sum is 34.

Adding to 155421152440 its reverse (44251124551), we get a palindrome (199672276991).

The spelling of 155421152440 in words is "one hundred fifty-five billion, four hundred twenty-one million, one hundred fifty-two thousand, four hundred forty".