261322542 has 96 divisors (see below), whose sum is σ = 654544800. Its totient is φ = 74670336.

The previous prime is 261322541. The next prime is 261322543. The reversal of 261322542 is 245223162.

It is a happy number.

261322542 is a `hidden beast` number, since 2 + 613 + 2 + 2 + 5 + 42 = 666.

It is an interprime number because it is at equal distance from previous prime (261322541) and next prime (261322543).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261322541) 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, 235084 + ... + 236192.

It is an arithmetic number, because the mean of its divisors is an integer number (6818175).

Almost surely, 2^261322542 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261322542, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (327272400).

261322542 is an abundant number, since it is smaller than the sum of its proper divisors (393222258).

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

261322542 is a wasteful number, since it uses less digits than its factorization.

261322542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1202 (or 1199 counting only the distinct ones).

The product of its digits is 5760, while the sum is 27.

The square root of 261322542 is about 16165.4737635493. The cubic root of 261322542 is about 639.3307962721.

The spelling of 261322542 in words is "two hundred sixty-one million, three hundred twenty-two thousand, five hundred forty-two".