61515551087 has 2 divisors, whose sum is σ = 61515551088. Its totient is φ = 61515551086.

The previous prime is 61515551021. The next prime is 61515551101. The reversal of 61515551087 is 78015551516.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 61515551087 - 2³⁴ = 44335681903 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61515551887) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30757775543 + 30757775544.

It is an arithmetic number, because the mean of its divisors is an integer number (30757775544).

Almost surely, 2^61515551087 is an apocalyptic number.

61515551087 is a deficient number, since it is larger than the sum of its proper divisors (1).

61515551087 is an equidigital number, since it uses as much as digits as its factorization.

61515551087 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 210000, while the sum is 44.

The spelling of 61515551087 in words is "sixty-one billion, five hundred fifteen million, five hundred fifty-one thousand, eighty-seven".