11721434553 has 6 divisors (see below), whose sum is σ = 16930961034. Its totient is φ = 7814289696.

The previous prime is 11721434551. The next prime is 11721434563. The reversal of 11721434553 is 35543412711.

11721434553 is a `hidden beast` number, since 1 + 1 + 72 + 1 + 4 + 34 + 553 = 666.

It can be written as a sum of positive squares in only one way, i.e., 9659548089 + 2061886464 = 98283^2 + 45408^2 .

It is not a de Polignac number, because 11721434553 - 2¹ = 11721434551 is a prime.

It is not an unprimeable number, because it can be changed into a prime (11721434551) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 651190800 + ... + 651190817.

It is an arithmetic number, because the mean of its divisors is an integer number (2821826839).

Almost surely, 2^11721434553 is an apocalyptic number.

It is an amenable number.

11721434553 is a deficient number, since it is larger than the sum of its proper divisors (5209526481).

11721434553 is a wasteful number, since it uses less digits than its factorization.

11721434553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1302381623 (or 1302381620 counting only the distinct ones).

The product of its digits is 50400, while the sum is 36.

The spelling of 11721434553 in words is "eleven billion, seven hundred twenty-one million, four hundred thirty-four thousand, five hundred fifty-three".