1621901489 has 16 divisors (see below), whose sum is σ = 1788375120. Its totient is φ = 1461749760.

The previous prime is 1621901483. The next prime is 1621901527. The reversal of 1621901489 is 9841091261.

It can be written as a sum of positive squares in 8 ways, for example, as 99341089 + 1522560400 = 9967^2 + 39020^2 .

It is a cyclic number.

It is not a de Polignac number, because 1621901489 - 2⁸ = 1621901233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1621901483) by changing a digit.

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 in 15 ways as a sum of consecutive naturals, for example, 101177 + ... + 116105.

It is an arithmetic number, because the mean of its divisors is an integer number (111773445).

Almost surely, 2^1621901489 is an apocalyptic number.

It is an amenable number.

1621901489 is a deficient number, since it is larger than the sum of its proper divisors (166473631).

1621901489 is a wasteful number, since it uses less digits than its factorization.

1621901489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15140.

The product of its (nonzero) digits is 31104, while the sum is 41.

The square root of 1621901489 is about 40272.8381046084. The cubic root of 1621901489 is about 1174.9196236554.

The spelling of 1621901489 in words is "one billion, six hundred twenty-one million, nine hundred one thousand, four hundred eighty-nine".