11111345531 has 32 divisors (see below), whose sum is σ = 13626869760. Its totient is φ = 8921721600.

The previous prime is 11111345519. The next prime is 11111345543. The reversal of 11111345531 is 13554311111.

It is an interprime number because it is at equal distance from previous prime (11111345519) and next prime (11111345543).

It is not a de Polignac number, because 11111345531 - 2⁶ = 11111345467 is a prime.

It is a super-2 number, since 2×11111345531² (a number of 21 digits) contains 22 as substring.

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 11111345531.

It is not an unprimeable number, because it can be changed into a prime (11111345131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 380456 + ... + 408618.

It is an arithmetic number, because the mean of its divisors is an integer number (425839680).

Almost surely, 2^11111345531 is an apocalyptic number.

11111345531 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

11111345531 is a deficient number, since it is larger than the sum of its proper divisors (2515524229).

11111345531 is a wasteful number, since it uses less digits than its factorization.

11111345531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28307.

The product of its digits is 900, while the sum is 26.

Adding to 11111345531 its reverse (13554311111), we get a palindrome (24665656642).

It can be divided in two parts, 1111 and 1345531, that multiplied together give a palindrome (1494884941).

The spelling of 11111345531 in words is "eleven billion, one hundred eleven million, three hundred forty-five thousand, five hundred thirty-one".