155821670400 has 648 divisors, whose sum is σ = 570670630992. Its totient is φ = 37486592000.

The previous prime is 155821670377. The next prime is 155821670423. The reversal of 155821670400 is 4076128551.

It is an interprime number because it is at equal distance from previous prime (155821670377) and next prime (155821670423).

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1189478335 + ... + 1189478465.

It is an arithmetic number, because the mean of its divisors is an integer number (880664554).

Almost surely, 2^155821670400 is an apocalyptic number.

155821670400 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 155821670400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (285335315496).

155821670400 is an abundant number, since it is smaller than the sum of its proper divisors (414848960592).

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

155821670400 is an equidigital number, since it uses as much as digits as its factorization.

155821670400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 200 (or 152 counting only the distinct ones).

The product of its (nonzero) digits is 67200, while the sum is 39.

Adding to 155821670400 its reverse (4076128551), we get a palindrome (159897798951).

The spelling of 155821670400 in words is "one hundred fifty-five billion, eight hundred twenty-one million, six hundred seventy thousand, four hundred".