61199947809 has 192 divisors, whose sum is σ = 122049607680. Its totient is φ = 28527759360.

The previous prime is 61199947801. The next prime is 61199947811. The reversal of 61199947809 is 90874999116.

61199947809 is a `hidden beast` number, since 61 + 19 + 99 + 478 + 0 + 9 = 666.

61199947809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 61199947809 - 2³ = 61199947801 is a prime.

It is a super-2 number, since 2×61199947809² (a number of 22 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (63) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (61199947801) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 51557914 + ... + 51559100.

It is an arithmetic number, because the mean of its divisors is an integer number (635675040).

Almost surely, 2^61199947809 is an apocalyptic number.

It is an amenable number.

61199947809 is a deficient number, since it is larger than the sum of its proper divisors (60849659871).

61199947809 is a wasteful number, since it uses less digits than its factorization.

61199947809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1380 (or 1377 counting only the distinct ones).

The product of its (nonzero) digits is 8817984, while the sum is 63.

The spelling of 61199947809 in words is "sixty-one billion, one hundred ninety-nine million, nine hundred forty-seven thousand, eight hundred nine".