61554207781415 has 8 divisors (see below), whose sum is σ = 73970420311008. Its totient is φ = 49173118909600.

The previous prime is 61554207781411. The next prime is 61554207781459. The reversal of 61554207781415 is 51418770245516.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 61554207781415 - 2² = 61554207781411 is a prime.

It is a super-2 number, since 2×61554207781415² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61554207781411) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8780910587 + ... + 8780917596.

It is an arithmetic number, because the mean of its divisors is an integer number (9246302538876).

Almost surely, 2^{61554207781415} is an apocalyptic number.

61554207781415 is a deficient number, since it is larger than the sum of its proper divisors (12416212529593).

61554207781415 is a wasteful number, since it uses less digits than its factorization.

61554207781415 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17561828889.

The product of its (nonzero) digits is 9408000, while the sum is 56.

The spelling of 61554207781415 in words is "sixty-one trillion, five hundred fifty-four billion, two hundred seven million, seven hundred eighty-one thousand, four hundred fifteen".