61530551 has 2 divisors, whose sum is σ = 61530552. Its totient is φ = 61530550.

The previous prime is 61530541. The next prime is 61530559. The reversal of 61530551 is 15503516.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61530551 - 2⁶ = 61530487 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 61530551.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61530559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30765275 + 30765276.

It is an arithmetic number, because the mean of its divisors is an integer number (30765276).

Almost surely, 2^61530551 is an apocalyptic number.

61530551 is a deficient number, since it is larger than the sum of its proper divisors (1).

61530551 is an equidigital number, since it uses as much as digits as its factorization.

61530551 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2250, while the sum is 26.

The square root of 61530551 is about 7844.1411894483. The cubic root of 61530551 is about 394.7876891409.

The spelling of 61530551 in words is "sixty-one million, five hundred thirty thousand, five hundred fifty-one".