1621822816 has 12 divisors (see below), whose sum is σ = 3192963732. Its totient is φ = 810911392.

The previous prime is 1621822757. The next prime is 1621822817. The reversal of 1621822816 is 6182281261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621822817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25340950 + ... + 25341013.

It is an arithmetic number, because the mean of its divisors is an integer number (266080311).

Almost surely, 2^1621822816 is an apocalyptic number.

1621822816 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1621822816 is a deficient number, since it is larger than the sum of its proper divisors (1571140916).

1621822816 is an equidigital number, since it uses as much as digits as its factorization.

1621822816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50681973 (or 50681965 counting only the distinct ones).

The product of its digits is 18432, while the sum is 37.

The square root of 1621822816 is about 40271.8613426298. The cubic root of 1621822816 is about 1174.9006262118.

The spelling of 1621822816 in words is "one billion, six hundred twenty-one million, eight hundred twenty-two thousand, eight hundred sixteen".