22061991 has 16 divisors (see below), whose sum is σ = 35080704. Its totient is φ = 12058464.

The previous prime is 22061989. The next prime is 22061993. The reversal of 22061991 is 19916022.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (22061989) and next prime (22061993).

It is not a de Polignac number, because 22061991 - 2¹ = 22061989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22061993) 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, 22356 + ... + 23321.

It is an arithmetic number, because the mean of its divisors is an integer number (2192544).

Almost surely, 2^22061991 is an apocalyptic number.

22061991 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

22061991 is a deficient number, since it is larger than the sum of its proper divisors (13018713).

22061991 is a wasteful number, since it uses less digits than its factorization.

22061991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45710.

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 22061991 is about 4697.0193740286. The cubic root of 22061991 is about 280.4668699214.

The spelling of 22061991 in words is "twenty-two million, sixty-one thousand, nine hundred ninety-one".