21777742 has 8 divisors (see below), whose sum is σ = 37333296. Its totient is φ = 9333312.

The previous prime is 21777727. The next prime is 21777751. The reversal of 21777742 is 24777712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 777763 + ... + 777790.

It is an arithmetic number, because the mean of its divisors is an integer number (4666662).

Almost surely, 2^21777742 is an apocalyptic number.

21777742 is a deficient number, since it is larger than the sum of its proper divisors (15555554).

21777742 is a wasteful number, since it uses less digits than its factorization.

21777742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1555562.

The product of its digits is 38416, while the sum is 37.

The square root of 21777742 is about 4666.6628333318. The cubic root of 21777742 is about 279.2571380146.

The spelling of 21777742 in words is "twenty-one million, seven hundred seventy-seven thousand, seven hundred forty-two".