621642541 has 4 divisors (see below), whose sum is σ = 669461212. Its totient is φ = 573823872.

The previous prime is 621642431. The next prime is 621642557. The reversal of 621642541 is 145246126.

It is a happy number.

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 85488516 + 536154025 = 9246^2 + 23155^2 .

It is a cyclic number.

It is not a de Polignac number, because 621642541 - 2¹⁷ = 621511469 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621642341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23909316 + ... + 23909341.

It is an arithmetic number, because the mean of its divisors is an integer number (167365303).

Almost surely, 2^621642541 is an apocalyptic number.

It is an amenable number.

621642541 is a deficient number, since it is larger than the sum of its proper divisors (47818671).

621642541 is a wasteful number, since it uses less digits than its factorization.

621642541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47818670.

The product of its digits is 11520, while the sum is 31.

The square root of 621642541 is about 24932.7603967150. The cubic root of 621642541 is about 853.4542439179.

Adding to 621642541 its reverse (145246126), we get a palindrome (766888667).

The spelling of 621642541 in words is "six hundred twenty-one million, six hundred forty-two thousand, five hundred forty-one".