261420020 has 12 divisors (see below), whose sum is σ = 548982084. Its totient is φ = 104568000.

The previous prime is 261419989. The next prime is 261420043. The reversal of 261420020 is 20024162.

It can be written as a sum of positive squares in 2 ways, for example, as 37797904 + 223622116 = 6148^2 + 14954^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6535481 + ... + 6535520.

It is an arithmetic number, because the mean of its divisors is an integer number (45748507).

Almost surely, 2^261420020 is an apocalyptic number.

261420020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261420020 is an abundant number, since it is smaller than the sum of its proper divisors (287562064).

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

261420020 is a wasteful number, since it uses less digits than its factorization.

261420020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13071010 (or 13071008 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 261420020 is about 16168.4884884147. The cubic root of 261420020 is about 639.4102803451.

Adding to 261420020 its reverse (20024162), we get a palindrome (281444182).

The spelling of 261420020 in words is "two hundred sixty-one million, four hundred twenty thousand, twenty".