691077031 has 2 divisors, whose sum is σ = 691077032. Its totient is φ = 691077030.

The previous prime is 691077011. The next prime is 691077053. The reversal of 691077031 is 130770196.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 691077031 - 2⁵ = 691076999 is a prime.

It is a super-2 number, since 2×691077031² = 955174925551549922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (691077001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345538515 + 345538516.

It is an arithmetic number, because the mean of its divisors is an integer number (345538516).

Almost surely, 2^691077031 is an apocalyptic number.

691077031 is a deficient number, since it is larger than the sum of its proper divisors (1).

691077031 is an equidigital number, since it uses as much as digits as its factorization.

691077031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7938, while the sum is 34.

The square root of 691077031 is about 26288.3440140302. The cubic root of 691077031 is about 884.1151235004.

The spelling of 691077031 in words is "six hundred ninety-one million, seventy-seven thousand, thirty-one".