9993547621 has 4 divisors (see below), whose sum is σ = 10010572992. Its totient is φ = 9976522252.

The previous prime is 9993547579. The next prime is 9993547651. The reversal of 9993547621 is 1267453999.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1267453999 = 7 ⋅181064857.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9993547621 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 (9993547651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8511805 + ... + 8512978.

It is an arithmetic number, because the mean of its divisors is an integer number (2502643248).

Almost surely, 2^9993547621 is an apocalyptic number.

It is an amenable number.

9993547621 is a deficient number, since it is larger than the sum of its proper divisors (17025371).

9993547621 is a wasteful number, since it uses less digits than its factorization.

9993547621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17025370.

The product of its digits is 3674160, while the sum is 55.

The square root of 9993547621 is about 99967.7328991710. The cubic root of 9993547621 is about 2153.9712160289.

The spelling of 9993547621 in words is "nine billion, nine hundred ninety-three million, five hundred forty-seven thousand, six hundred twenty-one".