9957621 has 4 divisors (see below), whose sum is σ = 13276832. Its totient is φ = 6638412.

The previous prime is 9957613. The next prime is 9957637. The reversal of 9957621 is 1267599.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 9957621 - 2³ = 9957613 is a prime.

It is a Duffinian number.

It is a Curzon number.

9957621 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 9957621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9957611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1659601 + ... + 1659606.

It is an arithmetic number, because the mean of its divisors is an integer number (3319208).

Almost surely, 2^9957621 is an apocalyptic number.

It is an amenable number.

9957621 is a deficient number, since it is larger than the sum of its proper divisors (3319211).

9957621 is a wasteful number, since it uses less digits than its factorization.

9957621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3319210.

The product of its digits is 34020, while the sum is 39.

The square root of 9957621 is about 3155.5698376046. The cubic root of 9957621 is about 215.1386954378.

The spelling of 9957621 in words is "nine million, nine hundred fifty-seven thousand, six hundred twenty-one".