1621069605 has 20 divisors (see below), whose sum is σ = 2905918092. Its totient is φ = 864570240.

The previous prime is 1621069573. The next prime is 1621069613. The reversal of 1621069605 is 5069601261.

1621069605 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 609447969 + 1011621636 = 24687^2 + 31806^2 .

It is not a de Polignac number, because 1621069605 - 2⁵ = 1621069573 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1621069605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2000916 + ... + 2001725.

Almost surely, 2^1621069605 is an apocalyptic number.

1621069605 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1621069605 is a deficient number, since it is larger than the sum of its proper divisors (1284848487).

1621069605 is an equidigital number, since it uses as much as digits as its factorization.

1621069605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4002658 (or 4002649 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 1621069605 is about 40262.5086774284. The cubic root of 1621069605 is about 1174.7187146206.

The spelling of 1621069605 in words is "one billion, six hundred twenty-one million, sixty-nine thousand, six hundred five".