1620881650 has 24 divisors (see below), whose sum is σ = 3027372084. Its totient is φ = 645657600.

The previous prime is 1620881611. The next prime is 1620881653. The reversal of 1620881650 is 561880261.

It can be written as a sum of positive squares in 6 ways, for example, as 968641129 + 652240521 = 31123^2 + 25539^2 .

It is not an unprimeable number, because it can be changed into a prime (1620881653) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 55207 + ... + 79306.

Almost surely, 2^1620881650 is an apocalyptic number.

1620881650 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1620881650 is a deficient number, since it is larger than the sum of its proper divisors (1406490434).

1620881650 is a wasteful number, since it uses less digits than its factorization.

1620881650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134766 (or 134761 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 37.

The square root of 1620881650 is about 40260.1744904316. The cubic root of 1620881650 is about 1174.6733119249.

The spelling of 1620881650 in words is "one billion, six hundred twenty million, eight hundred eighty-one thousand, six hundred fifty".