261504546420 has 144 divisors (see below), whose sum is σ = 834599989440. Its totient is φ = 60982391808.

The previous prime is 261504546403. The next prime is 261504546421. The reversal of 261504546420 is 24645405162.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261504546421) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 486009 + ... + 871328.

It is an arithmetic number, because the mean of its divisors is an integer number (5795833260).

Almost surely, 2^261504546420 is an apocalyptic number.

261504546420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261504546420 is an abundant number, since it is smaller than the sum of its proper divisors (573095443020).

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

261504546420 is a wasteful number, since it uses less digits than its factorization.

261504546420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1357394 (or 1357379 counting only the distinct ones).

The product of its (nonzero) digits is 230400, while the sum is 39.

The spelling of 261504546420 in words is "two hundred sixty-one billion, five hundred four million, five hundred forty-six thousand, four hundred twenty".