61978356 has 36 divisors (see below), whose sum is σ = 170911104. Its totient is φ = 18781200.

The previous prime is 61978349. The next prime is 61978363. The reversal of 61978356 is 65387916.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (61978349) and next prime (61978363).

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×61978356² = 7682633224925472, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 77860 + ... + 78651.

Almost surely, 2^61978356 is an apocalyptic number.

61978356 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

61978356 is an abundant number, since it is smaller than the sum of its proper divisors (108932748).

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

61978356 is a wasteful number, since it uses less digits than its factorization.

61978356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156532 (or 156527 counting only the distinct ones).

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

The square root of 61978356 is about 7872.6333586672. The cubic root of 61978356 is about 395.7430993679.

The spelling of 61978356 in words is "sixty-one million, nine hundred seventy-eight thousand, three hundred fifty-six".