21266554515 has 32 divisors (see below), whose sum is σ = 37594492416. Its totient is φ = 10210844160.

The previous prime is 21266554489. The next prime is 21266554531. The reversal of 21266554515 is 51545566212.

It is not a de Polignac number, because 21266554515 - 2⁵ = 21266554483 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1807141 + ... + 1818870.

It is an arithmetic number, because the mean of its divisors is an integer number (1174827888).

Almost surely, 2^21266554515 is an apocalyptic number.

21266554515 is a deficient number, since it is larger than the sum of its proper divisors (16327937901).

21266554515 is a wasteful number, since it uses less digits than its factorization.

21266554515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3626059.

The product of its digits is 360000, while the sum is 42.

The spelling of 21266554515 in words is "twenty-one billion, two hundred sixty-six million, five hundred fifty-four thousand, five hundred fifteen".