61777890 has 48 divisors (see below), whose sum is σ = 166578048. Its totient is φ = 16473456.

The previous prime is 61777889. The next prime is 61777943. The reversal of 61777890 is 9877716.

It is a happy number.

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10282 + ... + 15141.

It is an arithmetic number, because the mean of its divisors is an integer number (3470376).

Almost surely, 2^61777890 is an apocalyptic number.

61777890 is an abundant number, since it is smaller than the sum of its proper divisors (104800158).

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

61777890 is a wasteful number, since it uses less digits than its factorization.

61777890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25445 (or 25433 counting only the distinct ones).

The product of its (nonzero) digits is 148176, while the sum is 45.

The square root of 61777890 is about 7859.8912206213. The cubic root of 61777890 is about 395.3159678751.

The spelling of 61777890 in words is "sixty-one million, seven hundred seventy-seven thousand, eight hundred ninety".