61620090 has 64 divisors (see below), whose sum is σ = 170311680. Its totient is φ = 13976640.

The previous prime is 61620077. The next prime is 61620109. The reversal of 61620090 is 9002616.

It is a self number, because there is not a number n which added to its sum of digits gives 61620090.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28135 + ... + 30245.

It is an arithmetic number, because the mean of its divisors is an integer number (2661120).

Almost surely, 2^61620090 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61620090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85155840).

61620090 is an abundant number, since it is smaller than the sum of its proper divisors (108691590).

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

61620090 is a wasteful number, since it uses less digits than its factorization.

61620090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2267.

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 61620090 is about 7849.8464953144. The cubic root of 61620090 is about 394.9790941240.

It can be divided in two parts, 616 and 20090, that added together give a triangular number (20706 = T₂₀₃).

The spelling of 61620090 in words is "sixty-one million, six hundred twenty thousand, ninety".