621128402 has 4 divisors (see below), whose sum is σ = 931692606. Its totient is φ = 310564200.

The previous prime is 621128381. The next prime is 621128423. The reversal of 621128402 is 204821126.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (621128381) and next prime (621128423).

It can be written as a sum of positive squares in only one way, i.e., 377175241 + 243953161 = 19421^2 + 15619^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 155282099 + ... + 155282102.

Almost surely, 2^621128402 is an apocalyptic number.

621128402 is a deficient number, since it is larger than the sum of its proper divisors (310564204).

621128402 is a wasteful number, since it uses less digits than its factorization.

621128402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310564203.

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 621128402 is about 24922.4477529796. The cubic root of 621128402 is about 853.2188915470.

Adding to 621128402 its reverse (204821126), we get a palindrome (825949528).

The spelling of 621128402 in words is "six hundred twenty-one million, one hundred twenty-eight thousand, four hundred two".