61442456840 has 16 divisors (see below), whose sum is σ = 138245527980. Its totient is φ = 24576982720.

The previous prime is 61442456833. The next prime is 61442456849. The reversal of 61442456840 is 4865424416.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 59079135844 + 2363320996 = 243062^2 + 48614^2 .

It is a junction number, because it is equal to n+sod(n) for n = 61442456791 and 61442456800.

It is not an unprimeable number, because it can be changed into a prime (61442456849) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 768030671 + ... + 768030750.

Almost surely, 2^61442456840 is an apocalyptic number.

It is an amenable number.

61442456840 is an abundant number, since it is smaller than the sum of its proper divisors (76803071140).

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

61442456840 is a wasteful number, since it uses less digits than its factorization.

61442456840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1536061432 (or 1536061428 counting only the distinct ones).

The product of its (nonzero) digits is 737280, while the sum is 44.

The spelling of 61442456840 in words is "sixty-one billion, four hundred forty-two million, four hundred fifty-six thousand, eight hundred forty".