21017148977 has 8 divisors (see below), whose sum is σ = 24276493152. Its totient is φ = 17982587200.

The previous prime is 21017148973. The next prime is 21017148979. The reversal of 21017148977 is 77984171012.

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 21017148977 - 2² = 21017148973 is a prime.

It is a super-2 number, since 2×21017148977² (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 (21017148973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56195399 + ... + 56195772.

It is an arithmetic number, because the mean of its divisors is an integer number (3034561644).

Almost surely, 2^21017148977 is an apocalyptic number.

It is an amenable number.

21017148977 is a deficient number, since it is larger than the sum of its proper divisors (3259344175).

21017148977 is a wasteful number, since it uses less digits than its factorization.

21017148977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112391199.

The product of its (nonzero) digits is 197568, while the sum is 47.

The spelling of 21017148977 in words is "twenty-one billion, seventeen million, one hundred forty-eight thousand, nine hundred seventy-seven".