61621663 has 2 divisors, whose sum is σ = 61621664. Its totient is φ = 61621662.

The previous prime is 61621643. The next prime is 61621667. The reversal of 61621663 is 36612616.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61621663 - 2⁹ = 61621151 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61621667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30810831 + 30810832.

It is an arithmetic number, because the mean of its divisors is an integer number (30810832).

Almost surely, 2^61621663 is an apocalyptic number.

61621663 is a deficient number, since it is larger than the sum of its proper divisors (1).

61621663 is an equidigital number, since it uses as much as digits as its factorization.

61621663 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 31.

The square root of 61621663 is about 7849.9466877171. The cubic root of 61621663 is about 394.9824550237.

The spelling of 61621663 in words is "sixty-one million, six hundred twenty-one thousand, six hundred sixty-three".