261490451040 has 1536 divisors, whose sum is σ = 1192181760000. Its totient is φ = 52045701120.

The previous prime is 261490451017. The next prime is 261490451041. The reversal of 261490451040 is 40154094162.

261490451040 is a `hidden beast` number, since 2 + 6 + 14 + 90 + 4 + 510 + 40 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 261490450986 and 261490451004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261490451041) by changing a digit.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 524028711 + ... + 524029209.

It is an arithmetic number, because the mean of its divisors is an integer number (776160000).

Almost surely, 2^261490451040 is an apocalyptic number.

261490451040 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 261490451040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (596090880000).

261490451040 is an abundant number, since it is smaller than the sum of its proper divisors (930691308960).

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

261490451040 is a wasteful number, since it uses less digits than its factorization.

261490451040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 617 (or 603 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The spelling of 261490451040 in words is "two hundred sixty-one billion, four hundred ninety million, four hundred fifty-one thousand, forty".