621749396 has 6 divisors (see below), whose sum is σ = 1088061450. Its totient is φ = 310874696.

The previous prime is 621749389. The next prime is 621749437. The reversal of 621749396 is 693947126.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 359633296 + 262116100 = 18964^2 + 16190^2 .

It is a super-2 number, since 2×621749396² = 773144622852729632, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 621749396.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77718671 + ... + 77718678.

It is an arithmetic number, because the mean of its divisors is an integer number (181343575).

Almost surely, 2^621749396 is an apocalyptic number.

It is an amenable number.

621749396 is a deficient number, since it is larger than the sum of its proper divisors (466312054).

621749396 is a wasteful number, since it uses less digits than its factorization.

621749396 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155437353 (or 155437351 counting only the distinct ones).

The product of its digits is 489888, while the sum is 47.

The square root of 621749396 is about 24934.9031680494. The cubic root of 621749396 is about 853.5031415948.

The spelling of 621749396 in words is "six hundred twenty-one million, seven hundred forty-nine thousand, three hundred ninety-six".