61809630720 has 160 divisors (see below), whose sum is σ = 202939073568. Its totient is φ = 16037019648.

The previous prime is 61809630713. The next prime is 61809630749. The reversal of 61809630720 is 2703690816.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (160).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 175402 + ... + 392918.

Almost surely, 2^61809630720 is an apocalyptic number.

61809630720 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 61809630720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101469536784).

61809630720 is an abundant number, since it is smaller than the sum of its proper divisors (141129442848).

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

61809630720 is a wasteful number, since it uses less digits than its factorization.

61809630720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 217580 (or 217564 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 42.

The spelling of 61809630720 in words is "sixty-one billion, eight hundred nine million, six hundred thirty thousand, seven hundred twenty".