1621432225 has 48 divisors (see below), whose sum is σ = 2337350400. Its totient is φ = 1092890880.

The previous prime is 1621432213. The next prime is 1621432229. The reversal of 1621432225 is 5222341261.

It is not a de Polignac number, because 1621432225 - 2¹⁷ = 1621301153 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1621432193 and 1621432202.

It is not an unprimeable number, because it can be changed into a prime (1621432229) by changing a digit.

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 47 ways as a sum of consecutive naturals, for example, 3185271 + ... + 3185779.

It is an arithmetic number, because the mean of its divisors is an integer number (48694800).

Almost surely, 2^1621432225 is an apocalyptic number.

It is an amenable number.

1621432225 is a deficient number, since it is larger than the sum of its proper divisors (715918175).

1621432225 is a wasteful number, since it uses less digits than its factorization.

1621432225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 802 (or 797 counting only the distinct ones).

The product of its digits is 5760, while the sum is 28.

The square root of 1621432225 is about 40267.0116224187. The cubic root of 1621432225 is about 1174.8062997435.

Adding to 1621432225 its reverse (5222341261), we get a palindrome (6843773486).

It can be divided in two parts, 1621 and 432225, that added together give a triangular number (433846 = T₉₃₁).

The spelling of 1621432225 in words is "one billion, six hundred twenty-one million, four hundred thirty-two thousand, two hundred twenty-five".