162721640 has 16 divisors (see below), whose sum is σ = 366123780. Its totient is φ = 65088640.

The previous prime is 162721633. The next prime is 162721651. The reversal of 162721640 is 46127261.

It can be written as a sum of positive squares in 2 ways, for example, as 161849284 + 872356 = 12722^2 + 934^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2033981 + ... + 2034060.

Almost surely, 2^162721640 is an apocalyptic number.

162721640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

162721640 is an abundant number, since it is smaller than the sum of its proper divisors (203402140).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

162721640 is a wasteful number, since it uses less digits than its factorization.

162721640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4068052 (or 4068048 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 29.

The square root of 162721640 is about 12756.2392577123. The cubic root of 162721640 is about 545.9444276071.

It can be divided in two parts, 162721 and 640, that added together give a palindrome (163361).

The spelling of 162721640 in words is "one hundred sixty-two million, seven hundred twenty-one thousand, six hundred forty".