621213442 has 4 divisors (see below), whose sum is σ = 931820166. Its totient is φ = 310606720.

The previous prime is 621213407. The next prime is 621213469. The reversal of 621213442 is 244312126.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 244312126 = 2 ⋅122156063.

It can be written as a sum of positive squares in only one way, i.e., 620458281 + 755161 = 24909^2 + 869^2 .

It is a super-2 number, since 2×621213442² = 771812281042974728, which contains 22 as substring.

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, 155303359 + ... + 155303362.

Almost surely, 2^621213442 is an apocalyptic number.

621213442 is a deficient number, since it is larger than the sum of its proper divisors (310606724).

621213442 is a wasteful number, since it uses less digits than its factorization.

621213442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310606723.

The product of its digits is 2304, while the sum is 25.

The square root of 621213442 is about 24924.1537870396. The cubic root of 621213442 is about 853.2578284363.

Adding to 621213442 its reverse (244312126), we get a palindrome (865525568).

The spelling of 621213442 in words is "six hundred twenty-one million, two hundred thirteen thousand, four hundred forty-two".