1621425 has 24 divisors (see below), whose sum is σ = 2888704. Its totient is φ = 797760.

The previous prime is 1621423. The next prime is 1621439. The reversal of 1621425 is 5241261.

1621425 = 155² + 156² + ... + 204².

It is not a de Polignac number, because 1621425 - 2¹ = 1621423 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1621421) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 144 + ... + 1806.

2^1621425 is an apocalyptic number.

1621425 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1621425 is a deficient number, since it is larger than the sum of its proper divisors (1267279).

1621425 is a wasteful number, since it uses less digits than its factorization.

1621425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1689 (or 1684 counting only the distinct ones).

The product of its digits is 480, while the sum is 21.

The square root of 1621425 is about 1273.3518759557. The cubic root of 1621425 is about 117.4804554787.

Adding to 1621425 its reverse (5241261), we get a palindrome (6862686).

The spelling of 1621425 in words is "one million, six hundred twenty-one thousand, four hundred twenty-five".