11501981 has 8 divisors (see below), whose sum is σ = 11867904. Its totient is φ = 11141200.

The previous prime is 11501881. The next prime is 11502019. The reversal of 11501981 is 18910511.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11501981 is a prime.

It is a super-2 number, since 2×11501981² = 264591133848722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 11501981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11501681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3536 + ... + 5958.

It is an arithmetic number, because the mean of its divisors is an integer number (1483488).

Almost surely, 2^11501981 is an apocalyptic number.

It is an amenable number.

11501981 is a deficient number, since it is larger than the sum of its proper divisors (365923).

11501981 is a wasteful number, since it uses less digits than its factorization.

11501981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2571.

The product of its (nonzero) digits is 360, while the sum is 26.

The square root of 11501981 is about 3391.4570615003. The cubic root of 11501981 is about 225.7308318152.

The spelling of 11501981 in words is "eleven million, five hundred one thousand, nine hundred eighty-one".