1561970000 has 100 divisors (see below), whose sum is σ = 3819043140. Its totient is φ = 618624000.

The previous prime is 1561969973. The next prime is 1561970009. The reversal of 1561970000 is 791651.

It is a happy number.

It can be written as a sum of positive squares in 10 ways, for example, as 785344576 + 776625424 = 28024^2 + 27868^2 .

It is a tau number, because it is divible by the number of its divisors (100).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561970009) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1089284 + ... + 1090716.

Almost surely, 2^1561970000 is an apocalyptic number.

1561970000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1561970000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1909521570).

1561970000 is an abundant number, since it is smaller than the sum of its proper divisors (2257073140).

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

1561970000 is a wasteful number, since it uses less digits than its factorization.

1561970000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1570 (or 1549 counting only the distinct ones).

The product of its (nonzero) digits is 1890, while the sum is 29.

The square root of 1561970000 is about 39521.7661548671. The cubic root of 1561970000 is about 1160.2659913214.

The spelling of 1561970000 in words is "one billion, five hundred sixty-one million, nine hundred seventy thousand".