21690835867240 has 16 divisors (see below), whose sum is σ = 48804380701380. Its totient is φ = 8676334346880.

The previous prime is 21690835867193. The next prime is 21690835867241. The reversal of 21690835867240 is 4276853809612.

It can be written as a sum of positive squares in 2 ways, for example, as 21134376561796 + 556459305444 = 4597214^2 + 745962^2 .

It is not an unprimeable number, because it can be changed into a prime (21690835867241) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 271135448301 + ... + 271135448380.

It is a 1-persistent number, because it is pandigital, but 2⋅21690835867240 = 43381671734480 is not.

Almost surely, 2^{21690835867240} is an apocalyptic number.

21690835867240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21690835867240 is an abundant number, since it is smaller than the sum of its proper divisors (27113544834140).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21690835867240 is a wasteful number, since it uses less digits than its factorization.

21690835867240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 542270896692 (or 542270896688 counting only the distinct ones).

The product of its (nonzero) digits is 34836480, while the sum is 61.

The spelling of 21690835867240 in words is "twenty-one trillion, six hundred ninety billion, eight hundred thirty-five million, eight hundred sixty-seven thousand, two hundred forty".