11445551 has 4 divisors (see below), whose sum is σ = 12325992. Its totient is φ = 10565112.

The previous prime is 11445529. The next prime is 11445557. The reversal of 11445551 is 15554411.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 11445551 - 2¹⁸ = 11183407 is a prime.

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 11445551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11445557) 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, 440201 + ... + 440226.

It is an arithmetic number, because the mean of its divisors is an integer number (3081498).

Almost surely, 2^11445551 is an apocalyptic number.

11445551 is a deficient number, since it is larger than the sum of its proper divisors (880441).

11445551 is an equidigital number, since it uses as much as digits as its factorization.

11445551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 880440.

The product of its digits is 2000, while the sum is 26.

The square root of 11445551 is about 3383.1273993156. The cubic root of 11445551 is about 225.3610729265.

Adding to 11445551 its reverse (15554411), we get a palindrome (26999962).

The spelling of 11445551 in words is "eleven million, four hundred forty-five thousand, five hundred fifty-one".