99978047 has 4 divisors (see below), whose sum is σ = 107668680. Its totient is φ = 92287416.

The previous prime is 99978041. The next prime is 99978059. The reversal of 99978047 is 74087999.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 99978047 - 2¹⁴ = 99961663 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 99978047.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99978041) 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, 3845297 + ... + 3845322.

It is an arithmetic number, because the mean of its divisors is an integer number (26917170).

Almost surely, 2^99978047 is an apocalyptic number.

99978047 is a deficient number, since it is larger than the sum of its proper divisors (7690633).

99978047 is a wasteful number, since it uses less digits than its factorization.

99978047 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7690632.

The product of its (nonzero) digits is 1143072, while the sum is 53.

The square root of 99978047 is about 9998.9022897516. The cubic root of 99978047 is about 464.1249152756.

The spelling of 99978047 in words is "ninety-nine million, nine hundred seventy-eight thousand, forty-seven".