61621590 has 64 divisors (see below), whose sum is σ = 151990272. Its totient is φ = 15984000.

The previous prime is 61621589. The next prime is 61621597. The reversal of 61621590 is 9512616.

61621590 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61621597) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 276219 + ... + 276441.

It is an arithmetic number, because the mean of its divisors is an integer number (2374848).

Almost surely, 2^61621590 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61621590, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (75995136).

61621590 is an abundant number, since it is smaller than the sum of its proper divisors (90368682).

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

61621590 is a wasteful number, since it uses less digits than its factorization.

61621590 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 445.

The product of its (nonzero) digits is 3240, while the sum is 30.

The square root of 61621590 is about 7849.9420380026. The cubic root of 61621590 is about 394.9822990519.

The spelling of 61621590 in words is "sixty-one million, six hundred twenty-one thousand, five hundred ninety".