1621199444 has 6 divisors (see below), whose sum is σ = 2837099034. Its totient is φ = 810599720.

The previous prime is 1621199429. The next prime is 1621199473. The reversal of 1621199444 is 4449911261.

It can be written as a sum of positive squares in only one way, i.e., 1303932100 + 317267344 = 36110^2 + 17812^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202649927 + ... + 202649934.

It is an arithmetic number, because the mean of its divisors is an integer number (472849839).

Almost surely, 2^1621199444 is an apocalyptic number.

It is an amenable number.

1621199444 is a deficient number, since it is larger than the sum of its proper divisors (1215899590).

1621199444 is a wasteful number, since it uses less digits than its factorization.

1621199444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 405299865 (or 405299863 counting only the distinct ones).

The product of its digits is 62208, while the sum is 41.

The square root of 1621199444 is about 40264.1210508810. The cubic root of 1621199444 is about 1174.7500766774.

The spelling of 1621199444 in words is "one billion, six hundred twenty-one million, one hundred ninety-nine thousand, four hundred forty-four".