61857990 has 24 divisors (see below), whose sum is σ = 160831008. Its totient is φ = 16495440.

The previous prime is 61857979. The next prime is 61857997. The reversal of 61857990 is 9975816.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61857997) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 343566 + ... + 343745.

It is an arithmetic number, because the mean of its divisors is an integer number (6701292).

Almost surely, 2^61857990 is an apocalyptic number.

61857990 is an abundant number, since it is smaller than the sum of its proper divisors (98973018).

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

61857990 is a wasteful number, since it uses less digits than its factorization.

61857990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 687324 (or 687321 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 45.

The square root of 61857990 is about 7864.9850603800. The cubic root of 61857990 is about 395.4867470625.

The spelling of 61857990 in words is "sixty-one million, eight hundred fifty-seven thousand, nine hundred ninety".