361721 has 4 divisors (see below), whose sum is σ = 377472. Its totient is φ = 345972.

The previous prime is 361687. The next prime is 361723. The reversal of 361721 is 127163.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 361721 - 2¹⁸ = 99577 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 361693 and 361702.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 361721.

It is not an unprimeable number, because it can be changed into a prime (361723) 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, 7841 + ... + 7886.

It is an arithmetic number, because the mean of its divisors is an integer number (94368).

2³⁶¹⁷²¹ is an apocalyptic number.

It is an amenable number.

361721 is a deficient number, since it is larger than the sum of its proper divisors (15751).

361721 is a wasteful number, since it uses less digits than its factorization.

361721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15750.

The product of its digits is 252, while the sum is 20.

The square root of 361721 is about 601.4324567231. The cubic root of 361721 is about 71.2510454345.

Adding to 361721 its reverse (127163), we get a palindrome (488884).

It can be divided in two parts, 3617 and 21, that multiplied together give a palindrome (75957).

The spelling of 361721 in words is "three hundred sixty-one thousand, seven hundred twenty-one".