53661978 has 12 divisors (see below), whose sum is σ = 116267658. Its totient is φ = 17887320.

The previous prime is 53661973. The next prime is 53661991. The reversal of 53661978 is 87916635.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 34187409 + 19474569 = 5847^2 + 4413^2 .

It is not an unprimeable number, because it can be changed into a prime (53661973) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1490593 + ... + 1490628.

Almost surely, 2^53661978 is an apocalyptic number.

53661978 is an abundant number, since it is smaller than the sum of its proper divisors (62605680).

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

53661978 is a wasteful number, since it uses less digits than its factorization.

53661978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2981229 (or 2981226 counting only the distinct ones).

The product of its digits is 272160, while the sum is 45.

The square root of 53661978 is about 7325.4336390414. The cubic root of 53661978 is about 377.1859950411.

The spelling of 53661978 in words is "fifty-three million, six hundred sixty-one thousand, nine hundred seventy-eight".