61811897 has 4 divisors (see below), whose sum is σ = 70642176. Its totient is φ = 52981620.

The previous prime is 61811839. The next prime is 61811903. The reversal of 61811897 is 79811816.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 61811897 - 2¹⁸ = 61549753 is a prime.

It is a super-2 number, since 2×61811897² = 7641421221477218, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61811297) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4415129 + ... + 4415142.

It is an arithmetic number, because the mean of its divisors is an integer number (17660544).

Almost surely, 2^61811897 is an apocalyptic number.

It is an amenable number.

61811897 is a deficient number, since it is larger than the sum of its proper divisors (8830279).

61811897 is an equidigital number, since it uses as much as digits as its factorization.

61811897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8830278.

The product of its digits is 24192, while the sum is 41.

The square root of 61811897 is about 7862.0542480957. The cubic root of 61811897 is about 395.3884913627.

The spelling of 61811897 in words is "sixty-one million, eight hundred eleven thousand, eight hundred ninety-seven".