162987721 has 8 divisors (see below), whose sum is σ = 185850504. Its totient is φ = 141600000.

The previous prime is 162987709. The next prime is 162987767. The reversal of 162987721 is 127789261.

It can be written as a sum of positive squares in 4 ways, for example, as 32205625 + 130782096 = 5675^2 + 11436^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 162987721 - 2⁵ = 162987689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (162987421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 368530 + ... + 368971.

It is an arithmetic number, because the mean of its divisors is an integer number (23231313).

Almost surely, 2^162987721 is an apocalyptic number.

It is an amenable number.

162987721 is a deficient number, since it is larger than the sum of its proper divisors (22862783).

162987721 is a wasteful number, since it uses less digits than its factorization.

162987721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 737531.

The product of its digits is 84672, while the sum is 43.

The square root of 162987721 is about 12766.6644429937. The cubic root of 162987721 is about 546.2418400721.

The spelling of 162987721 in words is "one hundred sixty-two million, nine hundred eighty-seven thousand, seven hundred twenty-one".