51861899 has 2 divisors, whose sum is σ = 51861900. Its totient is φ = 51861898.

The previous prime is 51861877. The next prime is 51861907. The reversal of 51861899 is 99816815.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 51861899 - 2⁸ = 51861643 is a prime.

It is not a weakly prime, because it can be changed into another prime (51891899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25930949 + 25930950.

It is an arithmetic number, because the mean of its divisors is an integer number (25930950).

Almost surely, 2^51861899 is an apocalyptic number.

51861899 is a deficient number, since it is larger than the sum of its proper divisors (1).

51861899 is an equidigital number, since it uses as much as digits as its factorization.

51861899 is an evil number, because the sum of its binary digits is even.

The product of its digits is 155520, while the sum is 47.

The square root of 51861899 is about 7201.5206033171. The cubic root of 51861899 is about 372.9203974007.

The spelling of 51861899 in words is "fifty-one million, eight hundred sixty-one thousand, eight hundred ninety-nine".