1961438220 has 192 divisors, whose sum is σ = 7004067840. Its totient is φ = 446397696.

The previous prime is 1961438177. The next prime is 1961438233. The reversal of 1961438220 is 228341691.

1961438220 is a `hidden beast` number, since 1 + 9 + 614 + 38 + 2 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 993154 + ... + 995126.

It is an arithmetic number, because the mean of its divisors is an integer number (36479520).

Almost surely, 2^1961438220 is an apocalyptic number.

1961438220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1961438220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3502033920).

1961438220 is an abundant number, since it is smaller than the sum of its proper divisors (5042629620).

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

1961438220 is a wasteful number, since it uses less digits than its factorization.

1961438220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2261 (or 2253 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 1961438220 is about 44288.1273029240. The cubic root of 1961438220 is about 1251.7709766617.

The spelling of 1961438220 in words is "one billion, nine hundred sixty-one million, four hundred thirty-eight thousand, two hundred twenty".