61554191 has 2 divisors, whose sum is σ = 61554192. Its totient is φ = 61554190.

The previous prime is 61554133. The next prime is 61554197. The reversal of 61554191 is 19145516.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61554191 - 2¹⁸ = 61292047 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61554197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30777095 + 30777096.

It is an arithmetic number, because the mean of its divisors is an integer number (30777096).

Almost surely, 2^61554191 is an apocalyptic number.

61554191 is a deficient number, since it is larger than the sum of its proper divisors (1).

61554191 is an equidigital number, since it uses as much as digits as its factorization.

61554191 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5400, while the sum is 32.

The square root of 61554191 is about 7845.6479018625. The cubic root of 61554191 is about 394.8382417301.

The spelling of 61554191 in words is "sixty-one million, five hundred fifty-four thousand, one hundred ninety-one".