55951891 has 2 divisors, whose sum is σ = 55951892. Its totient is φ = 55951890.

The previous prime is 55951873. The next prime is 55951927. The reversal of 55951891 is 19815955.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 55951891 - 2⁵ = 55951859 is a prime.

It is a super-2 number, since 2×55951891² = 6261228212951762, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (55951871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27975945 + 27975946.

It is an arithmetic number, because the mean of its divisors is an integer number (27975946).

Almost surely, 2^55951891 is an apocalyptic number.

55951891 is a deficient number, since it is larger than the sum of its proper divisors (1).

55951891 is an equidigital number, since it uses as much as digits as its factorization.

55951891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 81000, while the sum is 43.

The square root of 55951891 is about 7480.0996651114. The cubic root of 55951891 is about 382.4766465871.

The spelling of 55951891 in words is "fifty-five million, nine hundred fifty-one thousand, eight hundred ninety-one".