1821508416 has 672 divisors, whose sum is σ = 7100620800. Its totient is φ = 432967680.

The previous prime is 1821508411. The next prime is 1821508417. The reversal of 1821508416 is 6148051281.

It is a tau number, because it is divible by the number of its divisors (672).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1821508411) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 30872995 + ... + 30873053.

It is an arithmetic number, because the mean of its divisors is an integer number (10566400).

Almost surely, 2^1821508416 is an apocalyptic number.

1821508416 is a gapful number since it is divisible by the number (16) 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 1821508416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3550310400).

1821508416 is an abundant number, since it is smaller than the sum of its proper divisors (5279112384).

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

1821508416 is a wasteful number, since it uses less digits than its factorization.

1821508416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147 (or 134 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 36.

The square root of 1821508416 is about 42679.1332620521. The cubic root of 1821508416 is about 1221.2663586308.

Adding to 1821508416 its reverse (6148051281), we get a palindrome (7969559697).

The spelling of 1821508416 in words is "one billion, eight hundred twenty-one million, five hundred eight thousand, four hundred sixteen".