21471957777 has 8 divisors (see below), whose sum is σ = 28639309216. Its totient is φ = 14309622432.

The previous prime is 21471957739. The next prime is 21471957791. The reversal of 21471957777 is 77775917412.

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

It is not a de Polignac number, because 21471957777 - 2⁷ = 21471957649 is a prime.

It is a super-2 number, since 2×21471957777² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21471957737) 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, 1244023 + ... + 1261164.

It is an arithmetic number, because the mean of its divisors is an integer number (3579913652).

Almost surely, 2^21471957777 is an apocalyptic number.

It is an amenable number.

21471957777 is a deficient number, since it is larger than the sum of its proper divisors (7167351439).

21471957777 is a wasteful number, since it uses less digits than its factorization.

21471957777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2508047.

The product of its digits is 6050520, while the sum is 57.

The spelling of 21471957777 in words is "twenty-one billion, four hundred seventy-one million, nine hundred fifty-seven thousand, seven hundred seventy-seven".