1621537345 has 8 divisors (see below), whose sum is σ = 1946082600. Its totient is φ = 1297071360.

The previous prime is 1621537277. The next prime is 1621537361. The reversal of 1621537345 is 5437351261.

It can be written as a sum of positive squares in 4 ways, for example, as 357663744 + 1263873601 = 18912^2 + 35551^2 .

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

It is not a de Polignac number, because 1621537345 - 2⁷ = 1621537217 is a prime.

It is a super-2 number, since 2×1621537345² = 5258766722459298050, which contains 22 as substring.

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, 43705 + ... + 71785.

It is an arithmetic number, because the mean of its divisors is an integer number (243260325).

Almost surely, 2^1621537345 is an apocalyptic number.

It is an amenable number.

1621537345 is a deficient number, since it is larger than the sum of its proper divisors (324545255).

1621537345 is a wasteful number, since it uses less digits than its factorization.

1621537345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39635.

The product of its digits is 75600, while the sum is 37.

The square root of 1621537345 is about 40268.3168880945. The cubic root of 1621537345 is about 1174.8316873746.

The spelling of 1621537345 in words is "one billion, six hundred twenty-one million, five hundred thirty-seven thousand, three hundred forty-five".