61031620 has 96 divisors (see below), whose sum is σ = 145297152. Its totient is φ = 21385728.

The previous prime is 61031617. The next prime is 61031651. The reversal of 61031620 is 2613016.

61031620 = T₂₀₅ + T₂₀₆ + ... + T₇₂₀.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 592489 + ... + 592591.

It is an arithmetic number, because the mean of its divisors is an integer number (1513512).

Almost surely, 2^61031620 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61031620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72648576).

61031620 is an abundant number, since it is smaller than the sum of its proper divisors (84265532).

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

61031620 is a wasteful number, since it uses less digits than its factorization.

61031620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221 (or 219 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 61031620 is about 7812.2736767218. The cubic root of 61031620 is about 393.7177240698.

Adding to 61031620 its reverse (2613016), we get a palindrome (63644636).

The spelling of 61031620 in words is "sixty-one million, thirty-one thousand, six hundred twenty".