61620239 has 2 divisors, whose sum is σ = 61620240. Its totient is φ = 61620238.

The previous prime is 61620227. The next prime is 61620241. The reversal of 61620239 is 93202616.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61620239 is a prime.

Together with 61620241, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61620269) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30810119 + 30810120.

It is an arithmetic number, because the mean of its divisors is an integer number (30810120).

Almost surely, 2^61620239 is an apocalyptic number.

61620239 is a deficient number, since it is larger than the sum of its proper divisors (1).

61620239 is an equidigital number, since it uses as much as digits as its factorization.

61620239 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 29.

The square root of 61620239 is about 7849.8559859401. The cubic root of 61620239 is about 394.9794124825.

The spelling of 61620239 in words is "sixty-one million, six hundred twenty thousand, two hundred thirty-nine".