1621885439 has 4 divisors (see below), whose sum is σ = 1625189160. Its totient is φ = 1618581720.

The previous prime is 1621885423. The next prime is 1621885501. The reversal of 1621885439 is 9345881261.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9345881261 = 33013 ⋅283097.

It is a cyclic number.

It is not a de Polignac number, because 1621885439 - 2⁴ = 1621885423 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1621885393 and 1621885402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621885039) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1651124 + ... + 1652105.

It is an arithmetic number, because the mean of its divisors is an integer number (406297290).

Almost surely, 2^1621885439 is an apocalyptic number.

1621885439 is a deficient number, since it is larger than the sum of its proper divisors (3303721).

1621885439 is an equidigital number, since it uses as much as digits as its factorization.

1621885439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3303720.

The product of its digits is 414720, while the sum is 47.

The square root of 1621885439 is about 40272.6388382981. The cubic root of 1621885439 is about 1174.9157480558.

The spelling of 1621885439 in words is "one billion, six hundred twenty-one million, eight hundred eighty-five thousand, four hundred thirty-nine".