61261885440 has 1664 divisors, whose sum is σ = 283080960000. Its totient is φ = 12485394432.

The previous prime is 61261885429. The next prime is 61261885453. The reversal of 61261885440 is 4458816216.

It is a happy number.

61261885440 is a `hidden beast` number, since 6 + 1 + 26 + 1 + 88 + 544 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 3224309751 + ... + 3224309769.

Almost surely, 2^61261885440 is an apocalyptic number.

61261885440 is a gapful number since it is divisible by the number (60) 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 61261885440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (141540480000).

61261885440 is an abundant number, since it is smaller than the sum of its proper divisors (221819074560).

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

61261885440 is a wasteful number, since it uses less digits than its factorization.

61261885440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95 (or 53 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 45.

The spelling of 61261885440 in words is "sixty-one billion, two hundred sixty-one million, eight hundred eighty-five thousand, four hundred forty".