61997690 has 16 divisors (see below), whose sum is σ = 111688200. Its totient is φ = 24778560.

The previous prime is 61997687. The next prime is 61997707. The reversal of 61997690 is 9679916.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 44849809 + 17147881 = 6697^2 + 4141^2 .

It is a super-2 number, since 2×61997690² = 7687427130672200, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17900 + ... + 21080.

Almost surely, 2^61997690 is an apocalyptic number.

61997690 is a deficient number, since it is larger than the sum of its proper divisors (49690510).

61997690 is a wasteful number, since it uses less digits than its factorization.

61997690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5137.

The product of its (nonzero) digits is 183708, while the sum is 47.

The square root of 61997690 is about 7873.8611874988. The cubic root of 61997690 is about 395.7842454610.

The spelling of 61997690 in words is "sixty-one million, nine hundred ninety-seven thousand, six hundred ninety".