261523431708 has 144 divisors (see below), whose sum is σ = 782050163328. Its totient is φ = 67255440000.

The previous prime is 261523431619. The next prime is 261523431727. The reversal of 261523431708 is 807134325162.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 261523431708.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 453103 + ... + 853433.

It is an arithmetic number, because the mean of its divisors is an integer number (5430903912).

Almost surely, 2^261523431708 is an apocalyptic number.

261523431708 is a gapful number since it is divisible by the number (28) 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 261523431708, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (391025081664).

261523431708 is an abundant number, since it is smaller than the sum of its proper divisors (520526731620).

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

261523431708 is a wasteful number, since it uses less digits than its factorization.

261523431708 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 400464 (or 400455 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 42.

The spelling of 261523431708 in words is "two hundred sixty-one billion, five hundred twenty-three million, four hundred thirty-one thousand, seven hundred eight".