164512403721 has 24 divisors (see below), whose sum is σ = 238265543880. Its totient is φ = 109381536000.

The previous prime is 164512403719. The next prime is 164512403743. The reversal of 164512403721 is 127304215461.

164512403721 is a `hidden beast` number, since 1 + 6 + 45 + 1 + 240 + 372 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 16567551225 + 147944852496 = 128715^2 + 384636^2 .

It is not a de Polignac number, because 164512403721 - 2¹ = 164512403719 is a prime.

It is a super-2 number, since 2×164512403721² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (164512403821) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5507695 + ... + 5537483.

It is an arithmetic number, because the mean of its divisors is an integer number (9927730995).

Almost surely, 2^164512403721 is an apocalyptic number.

It is an amenable number.

164512403721 is a deficient number, since it is larger than the sum of its proper divisors (73753140159).

164512403721 is a wasteful number, since it uses less digits than its factorization.

164512403721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31417 (or 31414 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The spelling of 164512403721 in words is "one hundred sixty-four billion, five hundred twelve million, four hundred three thousand, seven hundred twenty-one".