99678240 has 72 divisors (see below), whose sum is σ = 340156908. Its totient is φ = 26580480.

The previous prime is 99678233. The next prime is 99678247. The reversal of 99678240 is 4287699.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (99678233) and next prime (99678247).

It can be written as a sum of positive squares in 2 ways, for example, as 98485776 + 1192464 = 9924^2 + 1092^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (99678247) 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, 33171 + ... + 36050.

Almost surely, 2^99678240 is an apocalyptic number.

99678240 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

99678240 is an abundant number, since it is smaller than the sum of its proper divisors (240478668).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

99678240 is a wasteful number, since it uses less digits than its factorization.

99678240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69242 (or 69231 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 99678240 is about 9983.8990379511. The cubic root of 99678240 is about 463.6605225956.

The spelling of 99678240 in words is "ninety-nine million, six hundred seventy-eight thousand, two hundred forty".