61530320 has 30 divisors (see below), whose sum is σ = 143221302. Its totient is φ = 24584064.

The previous prime is 61530317. The next prime is 61530323. The reversal of 61530320 is 2303516.

It is an interprime number because it is at equal distance from previous prime (61530317) and next prime (61530323).

It can be written as a sum of positive squares in 3 ways, for example, as 25482304 + 36048016 = 5048^2 + 6004^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 61530292 and 61530301.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61530323) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 69722 + ... + 70598.

Almost surely, 2^61530320 is an apocalyptic number.

It is an amenable number.

61530320 is an abundant number, since it is smaller than the sum of its proper divisors (81690982).

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

61530320 is an frugal number, since it uses more digits than its factorization.

61530320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1767 (or 884 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 20.

The square root of 61530320 is about 7844.1264650693. The cubic root of 61530320 is about 394.7871950987.

Multiplying 61530320 by its sum of digits (20), we get a square (1230606400 = 35080²).

61530320 divided by its sum of digits (20) gives a square (3076516 = 1754²).

Adding to 61530320 its reverse (2303516), we get a palindrome (63833836).

The spelling of 61530320 in words is "sixty-one million, five hundred thirty thousand, three hundred twenty".