340021553 has 4 divisors (see below), whose sum is σ = 346437108. Its totient is φ = 333606000.

The previous prime is 340021531. The next prime is 340021559. The reversal of 340021553 is 355120043.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 103876864 + 236144689 = 10192^2 + 15367^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-340021553 is a prime.

It is a super-2 number, since 2×340021553² = 231229313009063618, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (340021559) 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, 3207698 + ... + 3207803.

It is an arithmetic number, because the mean of its divisors is an integer number (86609277).

Almost surely, 2^340021553 is an apocalyptic number.

It is an amenable number.

340021553 is a deficient number, since it is larger than the sum of its proper divisors (6415555).

340021553 is an equidigital number, since it uses as much as digits as its factorization.

340021553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6415554.

The product of its (nonzero) digits is 1800, while the sum is 23.

The square root of 340021553 is about 18439.6733430937. The cubic root of 340021553 is about 697.9679524042.

Adding to 340021553 its reverse (355120043), we get a palindrome (695141596).

The spelling of 340021553 in words is "three hundred forty million, twenty-one thousand, five hundred fifty-three".