1981580605 has 16 divisors (see below), whose sum is σ = 2598994944. Its totient is φ = 1443882240.

The previous prime is 1981580599. The next prime is 1981580609. The reversal of 1981580605 is 5060851891.

It is not a de Polignac number, because 1981580605 - 2³ = 1981580597 is a prime.

It is a super-2 number, since 2×1981580605² = 7853323388224332050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981580609) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 373377 + ... + 378646.

It is an arithmetic number, because the mean of its divisors is an integer number (162437184).

Almost surely, 2^1981580605 is an apocalyptic number.

It is an amenable number.

1981580605 is a deficient number, since it is larger than the sum of its proper divisors (617414339).

1981580605 is a wasteful number, since it uses less digits than its factorization.

1981580605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 752076.

The product of its (nonzero) digits is 86400, while the sum is 43.

The square root of 1981580605 is about 44514.9481073493. The cubic root of 1981580605 is about 1256.0412843358.

The spelling of 1981580605 in words is "one billion, nine hundred eighty-one million, five hundred eighty thousand, six hundred five".