21277619811 has 64 divisors (see below), whose sum is σ = 36822400000. Its totient is φ = 12138281568.

The previous prime is 21277619809. The next prime is 21277619863. The reversal of 21277619811 is 11891677212.

It is a happy number.

21277619811 is a `hidden beast` number, since 2 + 1 + 27 + 7 + 619 + 8 + 1 + 1 = 666.

It is not a de Polignac number, because 21277619811 - 2¹ = 21277619809 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21277619801) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6842325 + ... + 6845433.

It is an arithmetic number, because the mean of its divisors is an integer number (575350000).

Almost surely, 2^21277619811 is an apocalyptic number.

21277619811 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21277619811 is a deficient number, since it is larger than the sum of its proper divisors (15544780189).

21277619811 is an equidigital number, since it uses as much as digits as its factorization.

21277619811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3878 (or 3858 counting only the distinct ones).

The product of its digits is 84672, while the sum is 45.

The spelling of 21277619811 in words is "twenty-one billion, two hundred seventy-seven million, six hundred nineteen thousand, eight hundred eleven".