2561422620 has 96 divisors (see below), whose sum is σ = 7289243136. Its totient is φ = 671968000.

The previous prime is 2561422607. The next prime is 2561422627. The reversal of 2561422620 is 262241652.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2561422627) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1010755 + ... + 1013285.

It is an arithmetic number, because the mean of its divisors is an integer number (75929616).

Almost surely, 2^2561422620 is an apocalyptic number.

2561422620 is a gapful number since it is divisible by the number (20) 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 2561422620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3644621568).

2561422620 is an abundant number, since it is smaller than the sum of its proper divisors (4727820516).

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

2561422620 is a wasteful number, since it uses less digits than its factorization.

2561422620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2811 (or 2809 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 30.

The square root of 2561422620 is about 50610.4991083866. The cubic root of 2561422620 is about 1368.2341110397.

The spelling of 2561422620 in words is "two billion, five hundred sixty-one million, four hundred twenty-two thousand, six hundred twenty".