1581009402 has 48 divisors (see below), whose sum is σ = 3716254080. Its totient is φ = 447052032.

The previous prime is 1581009389. The next prime is 1581009403. The reversal of 1581009402 is 2049001851.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 1581009402.

It is not an unprimeable number, because it can be changed into a prime (1581009403) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 799 + ... + 56237.

It is an arithmetic number, because the mean of its divisors is an integer number (77421960).

Almost surely, 2^1581009402 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1581009402, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1858127040).

1581009402 is an abundant number, since it is smaller than the sum of its proper divisors (2135244678).

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

1581009402 is a wasteful number, since it uses less digits than its factorization.

1581009402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55555 (or 55548 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 30.

The square root of 1581009402 is about 39761.9089330480. The cubic root of 1581009402 is about 1164.9612620741.

The spelling of 1581009402 in words is "one billion, five hundred eighty-one million, nine thousand, four hundred two".