1621372916 has 6 divisors (see below), whose sum is σ = 2837402610. Its totient is φ = 810686456.

The previous prime is 1621372913. The next prime is 1621372927. The reversal of 1621372916 is 6192731261.

It can be written as a sum of positive squares in only one way, i.e., 884467600 + 736905316 = 29740^2 + 27146^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1621372916.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621372913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202671611 + ... + 202671618.

It is an arithmetic number, because the mean of its divisors is an integer number (472900435).

Almost surely, 2^1621372916 is an apocalyptic number.

It is an amenable number.

1621372916 is a deficient number, since it is larger than the sum of its proper divisors (1216029694).

1621372916 is a wasteful number, since it uses less digits than its factorization.

1621372916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 405343233 (or 405343231 counting only the distinct ones).

The product of its digits is 27216, while the sum is 38.

The square root of 1621372916 is about 40266.2751691785. The cubic root of 1621372916 is about 1174.7919754863.

The spelling of 1621372916 in words is "one billion, six hundred twenty-one million, three hundred seventy-two thousand, nine hundred sixteen".