12551621 has 12 divisors (see below), whose sum is σ = 13357836. Its totient is φ = 11784960.

The previous prime is 12551603. The next prime is 12551639. The reversal of 12551621 is 12615521.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (12551603) and next prime (12551639).

It can be written as a sum of positive squares in 2 ways, for example, as 8491396 + 4060225 = 2914^2 + 2015^2 .

It is not a de Polignac number, because 12551621 - 2⁶ = 12551557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12551641) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 35381 + ... + 35733.

It is an arithmetic number, because the mean of its divisors is an integer number (1113153).

Almost surely, 2^12551621 is an apocalyptic number.

It is an amenable number.

12551621 is a deficient number, since it is larger than the sum of its proper divisors (806215).

12551621 is an equidigital number, since it uses as much as digits as its factorization.

12551621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 452 (or 421 counting only the distinct ones).

The product of its digits is 600, while the sum is 23.

The square root of 12551621 is about 3542.8266962977. The cubic root of 12551621 is about 232.3984741917.

The spelling of 12551621 in words is "twelve million, five hundred fifty-one thousand, six hundred twenty-one".