61021911 has 4 divisors (see below), whose sum is σ = 81362552. Its totient is φ = 40681272.

The previous prime is 61021897. The next prime is 61021931. The reversal of 61021911 is 11912016.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 61021911 - 2¹⁰ = 61020887 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61021931) 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, 10170316 + ... + 10170321.

It is an arithmetic number, because the mean of its divisors is an integer number (20340638).

Almost surely, 2^61021911 is an apocalyptic number.

61021911 is a deficient number, since it is larger than the sum of its proper divisors (20340641).

61021911 is a wasteful number, since it uses less digits than its factorization.

61021911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20340640.

The product of its (nonzero) digits is 108, while the sum is 21.

The square root of 61021911 is about 7811.6522580053. The cubic root of 61021911 is about 393.6968452308.

Adding to 61021911 its reverse (11912016), we get a palindrome (72933927).

The spelling of 61021911 in words is "sixty-one million, twenty-one thousand, nine hundred eleven".