61981278 has 16 divisors (see below), whose sum is σ = 124649616. Its totient is φ = 20545920.

The previous prime is 61981277. The next prime is 61981279. The reversal of 61981278 is 87218916.

It is an interprime number because it is at equal distance from previous prime (61981277) and next prime (61981279).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61981277) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27451 + ... + 29622.

It is an arithmetic number, because the mean of its divisors is an integer number (7790601).

Almost surely, 2^61981278 is an apocalyptic number.

61981278 is an abundant number, since it is smaller than the sum of its proper divisors (62668338).

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

61981278 is a wasteful number, since it uses less digits than its factorization.

61981278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57259.

The product of its digits is 48384, while the sum is 42.

The square root of 61981278 is about 7872.8189360610. The cubic root of 61981278 is about 395.7493184376.

The spelling of 61981278 in words is "sixty-one million, nine hundred eighty-one thousand, two hundred seventy-eight".