61778390 has 32 divisors (see below), whose sum is σ = 116103456. Its totient is φ = 23645440.

The previous prime is 61778383. The next prime is 61778407. The reversal of 61778390 is 9387716.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20309 + ... + 23151.

It is an arithmetic number, because the mean of its divisors is an integer number (3628233).

Almost surely, 2^61778390 is an apocalyptic number.

61778390 is a deficient number, since it is larger than the sum of its proper divisors (54325066).

61778390 is a wasteful number, since it uses less digits than its factorization.

61778390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2944.

The product of its (nonzero) digits is 63504, while the sum is 41.

The square root of 61778390 is about 7859.9230276129. The cubic root of 61778390 is about 395.3170343702.

The spelling of 61778390 in words is "sixty-one million, seven hundred seventy-eight thousand, three hundred ninety".