68721405 has 8 divisors (see below), whose sum is σ = 109954272. Its totient is φ = 36651408.

The previous prime is 68721383. The next prime is 68721409. The reversal of 68721405 is 50412786.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 68721405 - 2¹⁶ = 68655869 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68721409) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2290699 + ... + 2290728.

It is an arithmetic number, because the mean of its divisors is an integer number (13744284).

Almost surely, 2^68721405 is an apocalyptic number.

It is an amenable number.

68721405 is a deficient number, since it is larger than the sum of its proper divisors (41232867).

68721405 is a wasteful number, since it uses less digits than its factorization.

68721405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4581435.

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 68721405 is about 8289.8374531712. The cubic root of 68721405 is about 409.6038310805.

The spelling of 68721405 in words is "sixty-eight million, seven hundred twenty-one thousand, four hundred five".