61978090 has 32 divisors (see below), whose sum is σ = 118797840. Its totient is φ = 23199744.

The previous prime is 61978079. The next prime is 61978097. The reversal of 61978090 is 9087916.

It can be written as a sum of positive squares in 8 ways, for example, as 26801329 + 35176761 = 5177^2 + 5931^2 .

It is not an unprimeable number, because it can be changed into a prime (61978097) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31866 + ... + 33754.

Almost surely, 2^61978090 is an apocalyptic number.

61978090 is a deficient number, since it is larger than the sum of its proper divisors (56819750).

61978090 is a wasteful number, since it uses less digits than its factorization.

61978090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2106.

The product of its (nonzero) digits is 27216, while the sum is 40.

The square root of 61978090 is about 7872.6164646831. The cubic root of 61978090 is about 395.7425332142.

The spelling of 61978090 in words is "sixty-one million, nine hundred seventy-eight thousand, ninety".