21506202164253 has 8 divisors (see below), whose sum is σ = 29921672576448. Its totient is φ = 13714099930784.

The previous prime is 21506202164221. The next prime is 21506202164257. The reversal of 21506202164253 is 35246120260512.

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 21506202164253 - 2⁵ = 21506202164221 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21506202164257) 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, 155842044600 + ... + 155842044737.

It is an arithmetic number, because the mean of its divisors is an integer number (3740209072056).

Almost surely, 2^{21506202164253} is an apocalyptic number.

21506202164253 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21506202164253 is a deficient number, since it is larger than the sum of its proper divisors (8415470412195).

21506202164253 is a wasteful number, since it uses less digits than its factorization.

21506202164253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 311684089363.

The product of its (nonzero) digits is 172800, while the sum is 39.

The spelling of 21506202164253 in words is "twenty-one trillion, five hundred six billion, two hundred two million, one hundred sixty-four thousand, two hundred fifty-three".