61721443 has 16 divisors (see below), whose sum is σ = 77483520. Its totient is φ = 47938176.

The previous prime is 61721437. The next prime is 61721449. The reversal of 61721443 is 34412716.

It is an interprime number because it is at equal distance from previous prime (61721437) and next prime (61721449).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61721443 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61721449) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7030 + ... + 13147.

It is an arithmetic number, because the mean of its divisors is an integer number (4842720).

Almost surely, 2^61721443 is an apocalyptic number.

61721443 is a deficient number, since it is larger than the sum of its proper divisors (15762077).

61721443 is a wasteful number, since it uses less digits than its factorization.

61721443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20226.

The product of its digits is 4032, while the sum is 28.

The square root of 61721443 is about 7856.2995742270. The cubic root of 61721443 is about 395.1955299635.

The spelling of 61721443 in words is "sixty-one million, seven hundred twenty-one thousand, four hundred forty-three".