99721670426 has 16 divisors (see below), whose sum is σ = 172713823296. Its totient is φ = 42297261696.

The previous prime is 99721670413. The next prime is 99721670431. The reversal of 99721670426 is 62407612799.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36715016 + ... + 36717731.

It is an arithmetic number, because the mean of its divisors is an integer number (10794613956).

Almost surely, 2^99721670426 is an apocalyptic number.

99721670426 is a deficient number, since it is larger than the sum of its proper divisors (72992152870).

99721670426 is a wasteful number, since it uses less digits than its factorization.

99721670426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73432853.

The product of its (nonzero) digits is 2286144, while the sum is 53.

The spelling of 99721670426 in words is "ninety-nine billion, seven hundred twenty-one million, six hundred seventy thousand, four hundred twenty-six".