61778236415 has 12 divisors (see below), whose sum is σ = 86237375256. Its totient is φ = 42362219088.

The previous prime is 61778236379. The next prime is 61778236511. The reversal of 61778236415 is 51463287716.

It is not a de Polignac number, because 61778236415 - 2¹² = 61778232319 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 126077789 + ... + 126078278.

It is an arithmetic number, because the mean of its divisors is an integer number (7186447938).

Almost surely, 2^61778236415 is an apocalyptic number.

61778236415 is a deficient number, since it is larger than the sum of its proper divisors (24459138841).

61778236415 is a wasteful number, since it uses less digits than its factorization.

61778236415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252156086 (or 252156079 counting only the distinct ones).

The product of its digits is 1693440, while the sum is 50.

The spelling of 61778236415 in words is "sixty-one billion, seven hundred seventy-eight million, two hundred thirty-six thousand, four hundred fifteen".