61720207 has 4 divisors (see below), whose sum is σ = 63848520. Its totient is φ = 59591896.

The previous prime is 61720187. The next prime is 61720213. The reversal of 61720207 is 70202716.

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 61720207 - 2⁷ = 61720079 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61720237) 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, 1064113 + ... + 1064170.

It is an arithmetic number, because the mean of its divisors is an integer number (15962130).

Almost surely, 2^61720207 is an apocalyptic number.

61720207 is a deficient number, since it is larger than the sum of its proper divisors (2128313).

61720207 is a wasteful number, since it uses less digits than its factorization.

61720207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2128312.

The product of its (nonzero) digits is 1176, while the sum is 25.

The square root of 61720207 is about 7856.2209108451. The cubic root of 61720207 is about 395.1928919557.

The spelling of 61720207 in words is "sixty-one million, seven hundred twenty thousand, two hundred seven".