164909900281 has 9 divisors (see below), whose sum is σ = 191837272431. Its totient is φ = 141348906552.

The previous prime is 164909900257. The next prime is 164909900291. The reversal of 164909900281 is 182009909461.

It is a happy number.

The square root of 164909900281 is 406091.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 149710955625 + 15198944656 = 386925^2 + 123284^2 .

It is not a de Polignac number, because 164909900281 - 2⁹ = 164909899769 is a prime.

It is a super-2 number, since 2×164909900281² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is not an unprimeable number, because it can be changed into a prime (164909900251) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2813631 + ... + 2871643.

Almost surely, 2^164909900281 is an apocalyptic number.

164909900281 is the 406091-st square number.

164909900281 is the 203046-th centered octagonal number.

It is an amenable number.

164909900281 is a deficient number, since it is larger than the sum of its proper divisors (26927372150).

164909900281 is an frugal number, since it uses more digits than its factorization.

164909900281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116040 (or 58020 counting only the distinct ones).

The product of its (nonzero) digits is 279936, while the sum is 49.

Multiplying 164909900281 by its sum of digits (49), we get a square (8080585113769 = 2842637²).

164909900281 divided by its sum of digits (49) gives a square (3365508169 = 58013²).

The spelling of 164909900281 in words is "one hundred sixty-four billion, nine hundred nine million, nine hundred thousand, two hundred eighty-one".