61724220 has 24 divisors (see below), whose sum is σ = 172827984. Its totient is φ = 16459776.

The previous prime is 61724213. The next prime is 61724227. The reversal of 61724220 is 2242716.

It is an interprime number because it is at equal distance from previous prime (61724213) and next prime (61724227).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61724227) 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, 514309 + ... + 514428.

It is an arithmetic number, because the mean of its divisors is an integer number (7201166).

Almost surely, 2^61724220 is an apocalyptic number.

61724220 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

61724220 is an abundant number, since it is smaller than the sum of its proper divisors (111103764).

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

61724220 is a wasteful number, since it uses less digits than its factorization.

61724220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1028749 (or 1028747 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 24.

The square root of 61724220 is about 7856.4763093896. The cubic root of 61724220 is about 395.2014568152.

Adding to 61724220 its reverse (2242716), we get a palindrome (63966936).

The spelling of 61724220 in words is "sixty-one million, seven hundred twenty-four thousand, two hundred twenty".