99993621 has 16 divisors (see below), whose sum is σ = 164092544. Its totient is φ = 52743744.

The previous prime is 99993611. The next prime is 99993671. The reversal of 99993621 is 12639999.

It is not a de Polignac number, because 99993621 - 2⁹ = 99993109 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99993601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 182866 + ... + 183411.

It is an arithmetic number, because the mean of its divisors is an integer number (10255784).

Almost surely, 2^99993621 is an apocalyptic number.

99993621 is a gapful number since it is divisible by the number (91) formed by its first and last digit.

It is an amenable number.

99993621 is a deficient number, since it is larger than the sum of its proper divisors (64098923).

99993621 is a wasteful number, since it uses less digits than its factorization.

99993621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 366300.

The product of its digits is 236196, while the sum is 48.

The square root of 99993621 is about 9999.6810449134. The cubic root of 99993621 is about 464.1490135864.

The spelling of 99993621 in words is "ninety-nine million, nine hundred ninety-three thousand, six hundred twenty-one".