21506346462646 has 16 divisors (see below), whose sum is σ = 32345105817600. Its totient is φ = 10724645346408.

The previous prime is 21506346462641. The next prime is 21506346462649. The reversal of 21506346462646 is 64626464360512.

It is a super-2 number, since 2×21506346462646² (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 (21506346462641) 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 7 ways as a sum of consecutive naturals, for example, 66347515 + ... + 66670873.

It is an arithmetic number, because the mean of its divisors is an integer number (2021569113600).

Almost surely, 2^{21506346462646} is an apocalyptic number.

21506346462646 is a deficient number, since it is larger than the sum of its proper divisors (10838759354954).

21506346462646 is a wasteful number, since it uses less digits than its factorization.

21506346462646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 411483.

The product of its (nonzero) digits is 29859840, while the sum is 55.

The spelling of 21506346462646 in words is "twenty-one trillion, five hundred six billion, three hundred forty-six million, four hundred sixty-two thousand, six hundred forty-six".