11071721015551 has 32 divisors (see below), whose sum is σ = 13036942330880. Its totient is φ = 9204070611456.

The previous prime is 11071721015491. The next prime is 11071721015567. The reversal of 11071721015551 is 15551012717011.

It is not a de Polignac number, because 11071721015551 - 2²³ = 11071712626943 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 11071721015551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11071721015951) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 111325735 + ... + 111425143.

It is an arithmetic number, because the mean of its divisors is an integer number (407404447840).

Almost surely, 2^{11071721015551} is an apocalyptic number.

11071721015551 is a deficient number, since it is larger than the sum of its proper divisors (1965221315329).

11071721015551 is an equidigital number, since it uses as much as digits as its factorization.

11071721015551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100823.

The product of its (nonzero) digits is 12250, while the sum is 37.

The spelling of 11071721015551 in words is "eleven trillion, seventy-one billion, seven hundred twenty-one million, fifteen thousand, five hundred fifty-one".