61830921672 has 160 divisors (see below), whose sum is σ = 186710139000. Its totient is φ = 19004046336.

The previous prime is 61830921653. The next prime is 61830921679. The reversal of 61830921672 is 27612903816.

61830921672 is a `hidden beast` number, since 61 + 8 + 309 + 216 + 72 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 50487393636 + 11343528036 = 224694^2 + 106506^2 .

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (61830921679) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 8833278 + ... + 8840274.

Almost surely, 2^61830921672 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 61830921672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93355069500).

61830921672 is an abundant number, since it is smaller than the sum of its proper divisors (124879217328).

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

61830921672 is a wasteful number, since it uses less digits than its factorization.

61830921672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8077 (or 8064 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The spelling of 61830921672 in words is "sixty-one billion, eight hundred thirty million, nine hundred twenty-one thousand, six hundred seventy-two".