61528391 has 2 divisors, whose sum is σ = 61528392. Its totient is φ = 61528390.

The previous prime is 61528367. The next prime is 61528393. The reversal of 61528391 is 19382516.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-61528391 is a prime.

Together with 61528393, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61528393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30764195 + 30764196.

It is an arithmetic number, because the mean of its divisors is an integer number (30764196).

Almost surely, 2^61528391 is an apocalyptic number.

61528391 is a deficient number, since it is larger than the sum of its proper divisors (1).

61528391 is an equidigital number, since it uses as much as digits as its factorization.

61528391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12960, while the sum is 35.

The square root of 61528391 is about 7844.0035058636. The cubic root of 61528391 is about 394.7830694770.

The spelling of 61528391 in words is "sixty-one million, five hundred twenty-eight thousand, three hundred ninety-one".