261438612120 has 384 divisors, whose sum is σ = 1017407044800. Its totient is φ = 59541350400.

The previous prime is 261438612101. The next prime is 261438612133. The reversal of 261438612120 is 21216834162.

It is a happy number.

261438612120 is a `hidden beast` number, since 2 + 6 + 1 + 4 + 38 + 612 + 1 + 2 + 0 = 666.

261438612120 is digitally balanced in base 7, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 14861730 + ... + 14879310.

Almost surely, 2^261438612120 is an apocalyptic number.

261438612120 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 261438612120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (508703522400).

261438612120 is an abundant number, since it is smaller than the sum of its proper divisors (755968432680).

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

261438612120 is a wasteful number, since it uses less digits than its factorization.

261438612120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17896 (or 17879 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The spelling of 261438612120 in words is "two hundred sixty-one billion, four hundred thirty-eight million, six hundred twelve thousand, one hundred twenty".