690817489821 has 24 divisors (see below), whose sum is σ = 1009938305376. Its totient is φ = 454965369120.

The previous prime is 690817489811. The next prime is 690817489841. The reversal of 690817489821 is 128984718096.

690817489821 is a `hidden beast` number, since 69 + 0 + 8 + 17 + 489 + 82 + 1 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-690817489821 is a prime.

It is a super-2 number, since 2×690817489821² (a number of 24 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (690817489811) 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, 17611851 + ... + 17651031.

It is an arithmetic number, because the mean of its divisors is an integer number (42080762724).

Almost surely, 2^690817489821 is an apocalyptic number.

It is an amenable number.

690817489821 is a deficient number, since it is larger than the sum of its proper divisors (319120815555).

690817489821 is a wasteful number, since it uses less digits than its factorization.

690817489821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 62873 (or 62870 counting only the distinct ones).

The product of its (nonzero) digits is 13934592, while the sum is 63.

The spelling of 690817489821 in words is "six hundred ninety billion, eight hundred seventeen million, four hundred eighty-nine thousand, eight hundred twenty-one".