28990011009981 has 16 divisors (see below), whose sum is σ = 46773799277184. Its totient is φ = 15591266425344.

The previous prime is 28990011009979. The next prime is 28990011010013. The reversal of 28990011009981 is 18990011009982.

It is not a de Polignac number, because 28990011009981 - 2¹ = 28990011009979 is a prime.

It is a super-2 number, since 2×28990011009981² (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 (28990011009941) 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, 40602255960 + ... + 40602256673.

It is an arithmetic number, because the mean of its divisors is an integer number (2923362454824).

Almost surely, 2^{28990011009981} is an apocalyptic number.

28990011009981 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

28990011009981 is a deficient number, since it is larger than the sum of its proper divisors (17783788267203).

28990011009981 is a wasteful number, since it uses less digits than its factorization.

28990011009981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81204512660.

The product of its (nonzero) digits is 839808, while the sum is 57.

Subtracting from 28990011009981 its reverse (18990011009982), we obtain a palindrome (9999999999999).

The spelling of 28990011009981 in words is "twenty-eight trillion, nine hundred ninety billion, eleven million, nine thousand, nine hundred eighty-one".