61617212720 has 40 divisors (see below), whose sum is σ = 163725738144. Its totient is φ = 21125901312.

The previous prime is 61617212689. The next prime is 61617212803. The reversal of 61617212720 is 2721271616.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (35).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55014809 + ... + 55015928.

Almost surely, 2^61617212720 is an apocalyptic number.

It is an amenable number.

61617212720 is an abundant number, since it is smaller than the sum of its proper divisors (102108525424).

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

61617212720 is a wasteful number, since it uses less digits than its factorization.

61617212720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110030757 (or 110030751 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 35.

The spelling of 61617212720 in words is "sixty-one billion, six hundred seventeen million, two hundred twelve thousand, seven hundred twenty".