1621017225 has 48 divisors (see below), whose sum is σ = 3047176000. Its totient is φ = 844421760.

The previous prime is 1621017221. The next prime is 1621017227. The reversal of 1621017225 is 5227101261.

1621017225 is a `hidden beast` number, since 1 + 621 + 0 + 17 + 2 + 25 = 666.

It is not a de Polignac number, because 1621017225 - 2² = 1621017221 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (1621017221) 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, 1101 + ... + 56949.

Almost surely, 2^1621017225 is an apocalyptic number.

1621017225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1621017225 is a deficient number, since it is larger than the sum of its proper divisors (1426158775).

1621017225 is a wasteful number, since it uses less digits than its factorization.

1621017225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55911 (or 55900 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 1621017225 is about 40261.8581910969. The cubic root of 1621017225 is about 1174.7060619809.

Adding to 1621017225 its reverse (5227101261), we get a palindrome (6848118486).

The spelling of 1621017225 in words is "one billion, six hundred twenty-one million, seventeen thousand, two hundred twenty-five".