9900254978 has 4 divisors (see below), whose sum is σ = 14850382470. Its totient is φ = 4950127488.

The previous prime is 9900254977. The next prime is 9900255017. The reversal of 9900254978 is 8794520099.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8794520099 = 167 ⋅52661797.

It can be written as a sum of positive squares in only one way, i.e., 6721212289 + 3179042689 = 81983^2 + 56383^2 .

It is not an unprimeable number, because it can be changed into a prime (9900254977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2475063743 + ... + 2475063746.

Almost surely, 2^9900254978 is an apocalyptic number.

9900254978 is a deficient number, since it is larger than the sum of its proper divisors (4950127492).

9900254978 is a wasteful number, since it uses less digits than its factorization.

9900254978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4950127491.

The product of its (nonzero) digits is 1632960, while the sum is 53.

The square root of 9900254978 is about 99500.0250150722. The cubic root of 9900254978 is about 2147.2476030761.

The spelling of 9900254978 in words is "nine billion, nine hundred million, two hundred fifty-four thousand, nine hundred seventy-eight".