21315680476 has 24 divisors (see below), whose sum is σ = 38512664064. Its totient is φ = 10312185840.

The previous prime is 21315680473. The next prime is 21315680483. The reversal of 21315680476 is 67408651312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21315680471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 891291 + ... + 914893.

It is an arithmetic number, because the mean of its divisors is an integer number (1604694336).

Almost surely, 2^21315680476 is an apocalyptic number.

It is an amenable number.

21315680476 is a deficient number, since it is larger than the sum of its proper divisors (17196983588).

21315680476 is a wasteful number, since it uses less digits than its factorization.

21315680476 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30921 (or 30919 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 43.

The spelling of 21315680476 in words is "twenty-one billion, three hundred fifteen million, six hundred eighty thousand, four hundred seventy-six".