21266423477 has 8 divisors (see below), whose sum is σ = 22906001664. Its totient is φ = 19627373808.

The previous prime is 21266423471. The next prime is 21266423509. The reversal of 21266423477 is 77432466212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21266423477 - 2⁶ = 21266423413 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21266423471) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46493 + ... + 211410.

It is an arithmetic number, because the mean of its divisors is an integer number (2863250208).

Almost surely, 2^21266423477 is an apocalyptic number.

It is an amenable number.

21266423477 is a deficient number, since it is larger than the sum of its proper divisors (1639578187).

21266423477 is a wasteful number, since it uses less digits than its factorization.

21266423477 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264259.

The product of its digits is 677376, while the sum is 44.

Adding to 21266423477 its reverse (77432466212), we get a palindrome (98698889689).

The spelling of 21266423477 in words is "twenty-one billion, two hundred sixty-six million, four hundred twenty-three thousand, four hundred seventy-seven".