691972 has 6 divisors (see below), whose sum is σ = 1210958. Its totient is φ = 345984.

The previous prime is 691949. The next prime is 691973. The reversal of 691972 is 279196.

It can be written as a sum of positive squares in only one way, i.e., 678976 + 12996 = 824^2 + 114^2 .

It is not an unprimeable number, because it can be changed into a prime (691973) by changing a digit.

691972 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 86493 + ... + 86500.

2⁶⁹¹⁹⁷² is an apocalyptic number.

It is an amenable number.

691972 is a deficient number, since it is larger than the sum of its proper divisors (518986).

691972 is a wasteful number, since it uses less digits than its factorization.

691972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172997 (or 172995 counting only the distinct ones).

The product of its digits is 6804, while the sum is 34.

The square root of 691972 is about 831.8485439069. The cubic root of 691972 is about 88.4496612235.

The spelling of 691972 in words is "six hundred ninety-one thousand, nine hundred seventy-two".