164553939821 has 2 divisors, whose sum is σ = 164553939822. Its totient is φ = 164553939820.

The previous prime is 164553939769. The next prime is 164553939833. The reversal of 164553939821 is 128939355461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 130421377321 + 34132562500 = 361139^2 + 184750^2 .

It is a cyclic number.

It is not a de Polignac number, because 164553939821 - 2¹⁴ = 164553923437 is a prime.

It is a super-2 number, since 2×164553939821² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (164553039821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82276969910 + 82276969911.

It is an arithmetic number, because the mean of its divisors is an integer number (82276969911).

Almost surely, 2^164553939821 is an apocalyptic number.

It is an amenable number.

164553939821 is a deficient number, since it is larger than the sum of its proper divisors (1).

164553939821 is an equidigital number, since it uses as much as digits as its factorization.

164553939821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6998400, while the sum is 56.

The spelling of 164553939821 in words is "one hundred sixty-four billion, five hundred fifty-three million, nine hundred thirty-nine thousand, eight hundred twenty-one".