99978001 has 2 divisors, whose sum is σ = 99978002. Its totient is φ = 99978000.

The previous prime is 99977989. The next prime is 99978017. The reversal of 99978001 is 10087999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59985025 + 39992976 = 7745^2 + 6324^2 .

It is a cyclic number.

It is not a de Polignac number, because 99978001 - 2⁷ = 99977873 is a prime.

It is not a weakly prime, because it can be changed into another prime (99978041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49989000 + 49989001.

It is an arithmetic number, because the mean of its divisors is an integer number (49989001).

Almost surely, 2^99978001 is an apocalyptic number.

It is an amenable number.

99978001 is a deficient number, since it is larger than the sum of its proper divisors (1).

99978001 is an equidigital number, since it uses as much as digits as its factorization.

99978001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40824, while the sum is 43.

The square root of 99978001 is about 9998.8999894988. The cubic root of 99978001 is about 464.1248440941.

The spelling of 99978001 in words is "ninety-nine million, nine hundred seventy-eight thousand, one".