21154532356513 has 8 divisors (see below), whose sum is σ = 21406894931240. Its totient is φ = 20903658647040.

The previous prime is 21154532356481. The next prime is 21154532356537. The reversal of 21154532356513 is 31565323545112.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2563194384 + 21151969162129 = 50628^2 + 4599127^2 .

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 21154532356513 - 2⁵ = 21154532356481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21154532356213) 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, 372187728 + ... + 372244561.

It is an arithmetic number, because the mean of its divisors is an integer number (2675861866405).

Almost surely, 2^{21154532356513} is an apocalyptic number.

It is an amenable number.

21154532356513 is a deficient number, since it is larger than the sum of its proper divisors (252362574727).

21154532356513 is a wasteful number, since it uses less digits than its factorization.

21154532356513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 744432627.

The product of its digits is 1620000, while the sum is 46.

The spelling of 21154532356513 in words is "twenty-one trillion, one hundred fifty-four billion, five hundred thirty-two million, three hundred fifty-six thousand, five hundred thirteen".