21356531773746 has 32 divisors (see below), whose sum is σ = 47068420660800. Its totient is φ = 6418420997184.

The previous prime is 21356531773663. The next prime is 21356531773747. The reversal of 21356531773746 is 64737713565312.

It is a super-2 number, since 2×21356531773746² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21356531773746.

It is not an unprimeable number, because it can be changed into a prime (21356531773747) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3183737221 + ... + 3183743928.

It is an arithmetic number, because the mean of its divisors is an integer number (1470888145650).

Almost surely, 2^{21356531773746} is an apocalyptic number.

21356531773746 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21356531773746 is an abundant number, since it is smaller than the sum of its proper divisors (25711888887054).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21356531773746 is a wasteful number, since it uses less digits than its factorization.

21356531773746 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6367481210.

The product of its digits is 66679200, while the sum is 60.

The spelling of 21356531773746 in words is "twenty-one trillion, three hundred fifty-six billion, five hundred thirty-one million, seven hundred seventy-three thousand, seven hundred forty-six".