61438856724 has 240 divisors, whose sum is σ = 191241487360. Its totient is φ = 16829752320.

The previous prime is 61438856719. The next prime is 61438856747. The reversal of 61438856724 is 42765883416.

It is a happy number.

61438856724 is a `hidden beast` number, since 61 + 438 + 85 + 6 + 72 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 7659564 + ... + 7667580.

Almost surely, 2^61438856724 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61438856724, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95620743680).

61438856724 is an abundant number, since it is smaller than the sum of its proper divisors (129802630636).

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

61438856724 is a wasteful number, since it uses less digits than its factorization.

61438856724 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8180 (or 8169 counting only the distinct ones).

The product of its digits is 7741440, while the sum is 54.

The spelling of 61438856724 in words is "sixty-one billion, four hundred thirty-eight million, eight hundred fifty-six thousand, seven hundred twenty-four".