621621011 has 4 divisors (see below), whose sum is σ = 678132024. Its totient is φ = 565110000.

The previous prime is 621620999. The next prime is 621621037. The reversal of 621621011 is 110126126.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-621621011 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (621621041) 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, 28255490 + ... + 28255511.

It is an arithmetic number, because the mean of its divisors is an integer number (169533006).

Almost surely, 2^621621011 is an apocalyptic number.

621621011 is a deficient number, since it is larger than the sum of its proper divisors (56511013).

621621011 is a wasteful number, since it uses less digits than its factorization.

621621011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56511012.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 621621011 is about 24932.3286317183. The cubic root of 621621011 is about 853.4443909446. Note that the first 3 decimals are identical.

Adding to 621621011 its reverse (110126126), we get a palindrome (731747137).

The spelling of 621621011 in words is "six hundred twenty-one million, six hundred twenty-one thousand, eleven".