61553491 has 2 divisors, whose sum is σ = 61553492. Its totient is φ = 61553490.

The previous prime is 61553467. The next prime is 61553501. The reversal of 61553491 is 19435516.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61553491 - 2⁹ = 61552979 is a prime.

It is not a weakly prime, because it can be changed into another prime (61553411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30776745 + 30776746.

It is an arithmetic number, because the mean of its divisors is an integer number (30776746).

Almost surely, 2^61553491 is an apocalyptic number.

61553491 is a deficient number, since it is larger than the sum of its proper divisors (1).

61553491 is an equidigital number, since it uses as much as digits as its factorization.

61553491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16200, while the sum is 34.

The square root of 61553491 is about 7845.6032910159. The cubic root of 61553491 is about 394.8367450120.

The spelling of 61553491 in words is "sixty-one million, five hundred fifty-three thousand, four hundred ninety-one".