1621389312 has 208 divisors, whose sum is σ = 4889699360. Its totient is φ = 537477120.

The previous prime is 1621389281. The next prime is 1621389361. The reversal of 1621389312 is 2139831261.

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

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

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, 8957862 + ... + 8958042.

It is an arithmetic number, because the mean of its divisors is an integer number (23508170).

Almost surely, 2^1621389312 is an apocalyptic number.

1621389312 is a gapful number since it is divisible by the number (12) 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 1621389312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2444849680).

1621389312 is an abundant number, since it is smaller than the sum of its proper divisors (3268310048).

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

1621389312 is an frugal number, since it uses more digits than its factorization.

1621389312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226 (or 186 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 1621389312 is about 40266.4787633585. The cubic root of 1621389312 is about 1174.7959354687.

The spelling of 1621389312 in words is "one billion, six hundred twenty-one million, three hundred eighty-nine thousand, three hundred twelve".