1620889964 has 6 divisors (see below), whose sum is σ = 2836557444. Its totient is φ = 810444980.

The previous prime is 1620889961. The next prime is 1620889993. The reversal of 1620889964 is 4699880261.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (1620889961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 202611242 + ... + 202611249.

It is an arithmetic number, because the mean of its divisors is an integer number (472759574).

Almost surely, 2^1620889964 is an apocalyptic number.

It is an amenable number.

1620889964 is a deficient number, since it is larger than the sum of its proper divisors (1215667480).

1620889964 is a wasteful number, since it uses less digits than its factorization.

1620889964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405222495 (or 405222493 counting only the distinct ones).

The product of its (nonzero) digits is 1492992, while the sum is 53.

The square root of 1620889964 is about 40260.2777437017. The cubic root of 1620889964 is about 1174.6753203416.

The spelling of 1620889964 in words is "one billion, six hundred twenty million, eight hundred eighty-nine thousand, nine hundred sixty-four".