28010649640 has 32 divisors (see below), whose sum is σ = 63133240680. Its totient is φ = 11184832512.

The previous prime is 28010649637. The next prime is 28010649673. The reversal of 28010649640 is 4694601082.

It can be written as a sum of positive squares in 4 ways, for example, as 27997990276 + 12659364 = 167326^2 + 3558^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 28010649593 and 28010649602.

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, 583737 + ... + 629896.

Almost surely, 2^28010649640 is an apocalyptic number.

28010649640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28010649640 is an abundant number, since it is smaller than the sum of its proper divisors (35122591040).

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

28010649640 is a wasteful number, since it uses less digits than its factorization.

28010649640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1214221 (or 1214217 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 40.

The spelling of 28010649640 in words is "twenty-eight billion, ten million, six hundred forty-nine thousand, six hundred forty".