28601433721 has 24 divisors (see below), whose sum is σ = 34388565120. Its totient is φ = 23704666272.

The previous prime is 28601433713. The next prime is 28601433727. The reversal of 28601433721 is 12733410682.

It is a happy number.

It is not a de Polignac number, because 28601433721 - 2³ = 28601433713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28601433727) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 116335 + ... + 265963.

It is an arithmetic number, because the mean of its divisors is an integer number (1432856880).

Almost surely, 2^28601433721 is an apocalyptic number.

It is an amenable number.

28601433721 is a deficient number, since it is larger than the sum of its proper divisors (5787131399).

28601433721 is a wasteful number, since it uses less digits than its factorization.

28601433721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149773 (or 149766 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 37.

The spelling of 28601433721 in words is "twenty-eight billion, six hundred one million, four hundred thirty-three thousand, seven hundred twenty-one".