1561380157440 has 960 divisors, whose sum is σ = 5749914250080. Its totient is φ = 405138309120.

The previous prime is 1561380157439. The next prime is 1561380157451. The reversal of 1561380157440 is 447510831651.

1561380157440 is a `hidden beast` number, since 1 + 5 + 6 + 1 + 38 + 0 + 1 + 574 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (960).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 6478755720 + ... + 6478755960.

Almost surely, 2^{1561380157440} is an apocalyptic number.

1561380157440 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 1561380157440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2874957125040).

1561380157440 is an abundant number, since it is smaller than the sum of its proper divisors (4188534092640).

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

1561380157440 is a wasteful number, since it uses less digits than its factorization.

1561380157440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 460 (or 431 counting only the distinct ones).

The product of its (nonzero) digits is 403200, while the sum is 45.

The spelling of 1561380157440 in words is "one trillion, five hundred sixty-one billion, three hundred eighty million, one hundred fifty-seven thousand, four hundred forty".