2661220525 has 12 divisors (see below), whose sum is σ = 3413704500. Its totient is φ = 2055562880.

The previous prime is 2661220519. The next prime is 2661220553. The reversal of 2661220525 is 5250221662.

It is a happy number.

2661220525 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 6 ways, for example, as 54199044 + 2607021481 = 7362^2 + 51059^2 .

It is not a de Polignac number, because 2661220525 - 2³ = 2661220517 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1834600 + ... + 1836049.

It is an arithmetic number, because the mean of its divisors is an integer number (284475375).

Almost surely, 2^2661220525 is an apocalyptic number.

2661220525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

2661220525 is a deficient number, since it is larger than the sum of its proper divisors (752483975).

2661220525 is a wasteful number, since it uses less digits than its factorization.

2661220525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3670688 (or 3670683 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 31.

The square root of 2661220525 is about 51587.0189582612. The cubic root of 2661220525 is about 1385.7778693703. Note that the first 3 decimals are identical.

The spelling of 2661220525 in words is "two billion, six hundred sixty-one million, two hundred twenty thousand, five hundred twenty-five".