1561029400 has 96 divisors (see below), whose sum is σ = 4291020000. Its totient is φ = 516741120.

The previous prime is 1561029373. The next prime is 1561029409. The reversal of 1561029400 is 49201651.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561029409) 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, 21376 + ... + 59824.

It is an arithmetic number, because the mean of its divisors is an integer number (44698125).

Almost surely, 2^1561029400 is an apocalyptic number.

1561029400 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 1561029400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2145510000).

1561029400 is an abundant number, since it is smaller than the sum of its proper divisors (2729990600).

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

1561029400 is a wasteful number, since it uses less digits than its factorization.

1561029400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38501 (or 38492 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 1561029400 is about 39509.8645910107. The cubic root of 1561029400 is about 1160.0330450356.

The spelling of 1561029400 in words is "one billion, five hundred sixty-one million, twenty-nine thousand, four hundred".