140821645 has 4 divisors (see below), whose sum is σ = 168985980. Its totient is φ = 112657312.

The previous prime is 140821643. The next prime is 140821657. The reversal of 140821645 is 546128041.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 546128041 = 109 ⋅5010349.

It can be written as a sum of positive squares in 2 ways, for example, as 73925604 + 66896041 = 8598^2 + 8179^2 .

It is a cyclic number.

It is not a de Polignac number, because 140821645 - 2¹ = 140821643 is a prime.

It is a super-3 number, since 3×140821645³ (a number of 25 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (140821643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14082160 + ... + 14082169.

It is an arithmetic number, because the mean of its divisors is an integer number (42246495).

Almost surely, 2^140821645 is an apocalyptic number.

It is an amenable number.

140821645 is a deficient number, since it is larger than the sum of its proper divisors (28164335).

140821645 is an equidigital number, since it uses as much as digits as its factorization.

140821645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28164334.

The product of its (nonzero) digits is 7680, while the sum is 31.

The square root of 140821645 is about 11866.8296103045. The cubic root of 140821645 is about 520.2632358044.

Adding to 140821645 its reverse (546128041), we get a palindrome (686949686).

The spelling of 140821645 in words is "one hundred forty million, eight hundred twenty-one thousand, six hundred forty-five".