1621232505 has 12 divisors (see below), whose sum is σ = 2810136420. Its totient is φ = 864657312.

The previous prime is 1621232491. The next prime is 1621232527. The reversal of 1621232505 is 5052321261.

It is a happy number.

1621232505 is a `hidden beast` number, since 1 + 621 + 2 + 32 + 5 + 0 + 5 = 666.

1621232505 is digitally balanced in base 6, 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 468765801 + 1152466704 = 21651^2 + 33948^2 .

It is not a de Polignac number, because 1621232505 - 2⁷ = 1621232377 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18013650 + ... + 18013739.

It is an arithmetic number, because the mean of its divisors is an integer number (234178035).

Almost surely, 2^1621232505 is an apocalyptic number.

1621232505 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1621232505 is a deficient number, since it is larger than the sum of its proper divisors (1188903915).

1621232505 is a wasteful number, since it uses less digits than its factorization.

1621232505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36027400 (or 36027397 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 1621232505 is about 40264.5316004048. The cubic root of 1621232505 is about 1174.7580621535.

Adding to 1621232505 its reverse (5052321261), we get a palindrome (6673553766).

The spelling of 1621232505 in words is "one billion, six hundred twenty-one million, two hundred thirty-two thousand, five hundred five".