1621012016 has 80 divisors (see below), whose sum is σ = 3591895104. Its totient is φ = 702062592.

The previous prime is 1621011991. The next prime is 1621012027. The reversal of 1621012016 is 6102101261.

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, 2181341 + ... + 2182083.

Almost surely, 2^1621012016 is an apocalyptic number.

1621012016 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 1621012016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1795947552).

1621012016 is an abundant number, since it is smaller than the sum of its proper divisors (1970883088).

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

1621012016 is a wasteful number, since it uses less digits than its factorization.

1621012016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1398 (or 1392 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 1621012016 is about 40261.7935020287. The cubic root of 1621012016 is about 1174.7048037071.

Adding to 1621012016 its reverse (6102101261), we get a palindrome (7723113277).

The spelling of 1621012016 in words is "one billion, six hundred twenty-one million, twelve thousand, sixteen".