28400749881981 has 8 divisors (see below), whose sum is σ = 37870695245760. Its totient is φ = 18932318886432.

The previous prime is 28400749881967. The next prime is 28400749881991. The reversal of 28400749881981 is 18918894700482.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28400749881981 - 2³⁵ = 28366390143613 is a prime.

It is a super-2 number, since 2×28400749881981² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28400749881991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 378548296 + ... + 378623313.

It is an arithmetic number, because the mean of its divisors is an integer number (4733836905720).

Almost surely, 2^{28400749881981} is an apocalyptic number.

It is an amenable number.

28400749881981 is a deficient number, since it is larger than the sum of its proper divisors (9469945363779).

28400749881981 is a wasteful number, since it uses less digits than its factorization.

28400749881981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 757184115.

The product of its (nonzero) digits is 74317824, while the sum is 69.

The spelling of 28400749881981 in words is "twenty-eight trillion, four hundred billion, seven hundred forty-nine million, eight hundred eighty-one thousand, nine hundred eighty-one".