1621372345 has 8 divisors (see below), whose sum is σ = 1947573576. Its totient is φ = 1295813376.

The previous prime is 1621372307. The next prime is 1621372351. The reversal of 1621372345 is 5432731261.

It can be written as a sum of positive squares in 4 ways, for example, as 57881664 + 1563490681 = 7608^2 + 39541^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1621372345 - 2²⁹ = 1084501433 is a prime.

It is a super-2 number, since 2×1621372345² = 5257696562261598050, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1621372345.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 154992 + ... + 165121.

It is an arithmetic number, because the mean of its divisors is an integer number (243446697).

Almost surely, 2^1621372345 is an apocalyptic number.

It is an amenable number.

1621372345 is a deficient number, since it is larger than the sum of its proper divisors (326201231).

1621372345 is a wasteful number, since it uses less digits than its factorization.

1621372345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321131.

The product of its digits is 30240, while the sum is 34.

The square root of 1621372345 is about 40266.2680788771. The cubic root of 1621372345 is about 1174.7918375772.

The spelling of 1621372345 in words is "one billion, six hundred twenty-one million, three hundred seventy-two thousand, three hundred forty-five".