1621516318 has 16 divisors (see below), whose sum is σ = 2546104320. Its totient is φ = 773551800.

The previous prime is 1621516313. The next prime is 1621516319. The reversal of 1621516318 is 8136151261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1621516313) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 179778 + ... + 188581.

It is an arithmetic number, because the mean of its divisors is an integer number (159131520).

Almost surely, 2^1621516318 is an apocalyptic number.

1621516318 is a deficient number, since it is larger than the sum of its proper divisors (924588002).

1621516318 is a wasteful number, since it uses less digits than its factorization.

1621516318 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 368463.

The product of its digits is 8640, while the sum is 34.

The square root of 1621516318 is about 40268.0558010937. The cubic root of 1621516318 is about 1174.8266092116.

Adding to 1621516318 its reverse (8136151261), we get a palindrome (9757667579).

The spelling of 1621516318 in words is "one billion, six hundred twenty-one million, five hundred sixteen thousand, three hundred eighteen".