67721620 has 12 divisors (see below), whose sum is σ = 142215444. Its totient is φ = 27088640.

The previous prime is 67721597. The next prime is 67721653. The reversal of 67721620 is 2612776.

It can be written as a sum of positive squares in 2 ways, for example, as 33779344 + 33942276 = 5812^2 + 5826^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1693021 + ... + 1693060.

It is an arithmetic number, because the mean of its divisors is an integer number (11851287).

Almost surely, 2^67721620 is an apocalyptic number.

It is an amenable number.

67721620 is an abundant number, since it is smaller than the sum of its proper divisors (74493824).

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

67721620 is a wasteful number, since it uses less digits than its factorization.

67721620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3386090 (or 3386088 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 31.

The square root of 67721620 is about 8229.3146737745. The cubic root of 67721620 is about 407.6077625346.

The spelling of 67721620 in words is "sixty-seven million, seven hundred twenty-one thousand, six hundred twenty".