691093951 has 2 divisors, whose sum is σ = 691093952. Its totient is φ = 691093950.

The previous prime is 691093901. The next prime is 691093957. The reversal of 691093951 is 159390196.

691093951 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 691093951 - 2²¹ = 688996799 is a prime.

It is a super-2 number, since 2×691093951² = 955221698217580802, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 691093898 and 691093907.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (691093957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345546975 + 345546976.

It is an arithmetic number, because the mean of its divisors is an integer number (345546976).

Almost surely, 2^691093951 is an apocalyptic number.

691093951 is a deficient number, since it is larger than the sum of its proper divisors (1).

691093951 is an equidigital number, since it uses as much as digits as its factorization.

691093951 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 65610, while the sum is 43.

The square root of 691093951 is about 26288.6658276908. The cubic root of 691093951 is about 884.1223388590.

The spelling of 691093951 in words is "six hundred ninety-one million, ninety-three thousand, nine hundred fifty-one".