99721894 has 8 divisors (see below), whose sum is σ = 154740960. Its totient is φ = 48141576.

The previous prime is 99721891. The next prime is 99721907. The reversal of 99721894 is 49812799.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×99721894² = 19888912285894472, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99721891) 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, 859614 + ... + 859729.

It is an arithmetic number, because the mean of its divisors is an integer number (19342620).

Almost surely, 2^99721894 is an apocalyptic number.

99721894 is a deficient number, since it is larger than the sum of its proper divisors (55019066).

99721894 is a wasteful number, since it uses less digits than its factorization.

99721894 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1719374.

The product of its digits is 326592, while the sum is 49.

The square root of 99721894 is about 9986.0850186647. The cubic root of 99721894 is about 463.7281992934.

The spelling of 99721894 in words is "ninety-nine million, seven hundred twenty-one thousand, eight hundred ninety-four".