164943551 has 4 divisors (see below), whose sum is σ = 165189312. Its totient is φ = 164697792.

The previous prime is 164943523. The next prime is 164943577. The reversal of 164943551 is 155349461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 155349461 = 1097 ⋅141613.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-164943551 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (164945551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121871 + ... + 123216.

It is an arithmetic number, because the mean of its divisors is an integer number (41297328).

Almost surely, 2^164943551 is an apocalyptic number.

164943551 is a deficient number, since it is larger than the sum of its proper divisors (245761).

164943551 is an equidigital number, since it uses as much as digits as its factorization.

164943551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245760.

The product of its digits is 64800, while the sum is 38.

The square root of 164943551 is about 12843.0351163578. The cubic root of 164943551 is about 548.4181002616.

The spelling of 164943551 in words is "one hundred sixty-four million, nine hundred forty-three thousand, five hundred fifty-one".