28020335640 has 64 divisors (see below), whose sum is σ = 91702920960. Its totient is φ = 6792808320.

The previous prime is 28020335621. The next prime is 28020335641. The reversal of 28020335640 is 4653302082.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28020335641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10612444 + ... + 10615083.

It is an arithmetic number, because the mean of its divisors is an integer number (1432858140).

Almost surely, 2^28020335640 is an apocalyptic number.

28020335640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28020335640 is an abundant number, since it is smaller than the sum of its proper divisors (63682585320).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28020335640 is a wasteful number, since it uses less digits than its factorization.

28020335640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21227552 (or 21227548 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 33.

The spelling of 28020335640 in words is "twenty-eight billion, twenty million, three hundred thirty-five thousand, six hundred forty".