691954051555 has 16 divisors (see below), whose sum is σ = 905536759680. Its totient is φ = 504513330048.

The previous prime is 691954051553. The next prime is 691954051571. The reversal of 691954051555 is 555150459196.

It is not a de Polignac number, because 691954051555 - 2¹ = 691954051553 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 691954051496 and 691954051505.

It is not an unprimeable number, because it can be changed into a prime (691954051553) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 67371112 + ... + 67381381.

It is an arithmetic number, because the mean of its divisors is an integer number (56596047480).

Almost surely, 2^691954051555 is an apocalyptic number.

691954051555 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

691954051555 is a deficient number, since it is larger than the sum of its proper divisors (213582708125).

691954051555 is a wasteful number, since it uses less digits than its factorization.

691954051555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134752590.

The product of its (nonzero) digits is 6075000, while the sum is 55.

The spelling of 691954051555 in words is "six hundred ninety-one billion, nine hundred fifty-four million, fifty-one thousand, five hundred fifty-five".