21307461947823 has 64 divisors (see below), whose sum is σ = 29634658375680. Its totient is φ = 13609314081792.

The previous prime is 21307461947819. The next prime is 21307461947833. The reversal of 21307461947823 is 32874916470312.

It is not a de Polignac number, because 21307461947823 - 2² = 21307461947819 is a prime.

It is a super-2 number, since 2×21307461947823² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21307461947833) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 545723940 + ... + 545762982.

It is an arithmetic number, because the mean of its divisors is an integer number (463041537120).

Almost surely, 2^{21307461947823} is an apocalyptic number.

21307461947823 is a deficient number, since it is larger than the sum of its proper divisors (8327196427857).

21307461947823 is a wasteful number, since it uses less digits than its factorization.

21307461947823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39616.

The product of its (nonzero) digits is 12192768, while the sum is 57.

The spelling of 21307461947823 in words is "twenty-one trillion, three hundred seven billion, four hundred sixty-one million, nine hundred forty-seven thousand, eight hundred twenty-three".