697813821 has 24 divisors (see below), whose sum is σ = 1037123360. Its totient is φ = 451793376.

The previous prime is 697813811. The next prime is 697813849. The reversal of 697813821 is 128318796.

It is not a de Polignac number, because 697813821 - 2⁶ = 697813757 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (697813811) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 212490 + ... + 215748.

Almost surely, 2^697813821 is an apocalyptic number.

It is an amenable number.

697813821 is a deficient number, since it is larger than the sum of its proper divisors (339309539).

697813821 is a wasteful number, since it uses less digits than its factorization.

697813821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3945 (or 3942 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The square root of 697813821 is about 26416.1659027195. The cubic root of 697813821 is about 886.9786963274.

The spelling of 697813821 in words is "six hundred ninety-seven million, eight hundred thirteen thousand, eight hundred twenty-one".