10987981 has 4 divisors (see below), whose sum is σ = 11342464. Its totient is φ = 10633500.

The previous prime is 10987979. The next prime is 10988009. The reversal of 10987981 is 18978901.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 10987981 - 2¹ = 10987979 is a prime.

It is a super-2 number, since 2×10987981² = 241471452912722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10987931) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 177195 + ... + 177256.

It is an arithmetic number, because the mean of its divisors is an integer number (2835616).

Almost surely, 2^10987981 is an apocalyptic number.

It is an amenable number.

10987981 is a deficient number, since it is larger than the sum of its proper divisors (354483).

10987981 is an equidigital number, since it uses as much as digits as its factorization.

10987981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 354482.

The product of its (nonzero) digits is 36288, while the sum is 43.

The square root of 10987981 is about 3314.8123627138. The cubic root of 10987981 is about 222.3169794872.

The spelling of 10987981 in words is "ten million, nine hundred eighty-seven thousand, nine hundred eighty-one".