61721339 has 4 divisors (see below), whose sum is σ = 65352024. Its totient is φ = 58090656.

The previous prime is 61721333. The next prime is 61721353. The reversal of 61721339 is 93312716.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 61721339 - 2⁴ = 61721323 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61721333) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1815317 + ... + 1815350.

It is an arithmetic number, because the mean of its divisors is an integer number (16338006).

Almost surely, 2^61721339 is an apocalyptic number.

61721339 is a deficient number, since it is larger than the sum of its proper divisors (3630685).

61721339 is a wasteful number, since it uses less digits than its factorization.

61721339 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3630684.

The product of its digits is 6804, while the sum is 32.

The square root of 61721339 is about 7856.2929553321. The cubic root of 61721339 is about 395.1953079965.

The spelling of 61721339 in words is "sixty-one million, seven hundred twenty-one thousand, three hundred thirty-nine".