1581663450 has 48 divisors (see below), whose sum is σ = 3977798976. Its totient is φ = 415833600.

The previous prime is 1581663401. The next prime is 1581663481. The reversal of 1581663450 is 543661851.

It is a junction number, because it is equal to n+sod(n) for n = 1581663399 and 1581663408.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 63607 + ... + 84906.

It is an arithmetic number, because the mean of its divisors is an integer number (82870812).

Almost surely, 2^1581663450 is an apocalyptic number.

1581663450 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1581663450 is an abundant number, since it is smaller than the sum of its proper divisors (2396135526).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1581663450 is a wasteful number, since it uses less digits than its factorization.

1581663450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148599 (or 148594 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 39.

The square root of 1581663450 is about 39770.1326374454. The cubic root of 1581663450 is about 1165.1218842558.

The spelling of 1581663450 in words is "one billion, five hundred eighty-one million, six hundred sixty-three thousand, four hundred fifty".