1581402690 has 192 divisors, whose sum is σ = 5031936000. Its totient is φ = 349686720.

The previous prime is 1581402649. The next prime is 1581402703. The reversal of 1581402690 is 962041851.

It is a super-2 number, since 2×1581402690² = 5001668935878472200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 525811 + ... + 528809.

It is an arithmetic number, because the mean of its divisors is an integer number (26208000).

Almost surely, 2^1581402690 is an apocalyptic number.

1581402690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1581402690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2515968000).

1581402690 is an abundant number, since it is smaller than the sum of its proper divisors (3450533310).

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

1581402690 is a wasteful number, since it uses less digits than its factorization.

1581402690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3059 (or 3047 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 1581402690 is about 39766.8541627321. The cubic root of 1581402690 is about 1165.0578516956.

The spelling of 1581402690 in words is "one billion, five hundred eighty-one million, four hundred two thousand, six hundred ninety".