20401340155 has 16 divisors (see below), whose sum is σ = 29451559680. Its totient is φ = 13253200992.

The previous prime is 20401340143. The next prime is 20401340173. The reversal of 20401340155 is 55104310402.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20401340155 - 2⁷ = 20401340027 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15338689 + ... + 15340018.

It is an arithmetic number, because the mean of its divisors is an integer number (1840722480).

Almost surely, 2^20401340155 is an apocalyptic number.

20401340155 is a deficient number, since it is larger than the sum of its proper divisors (9050219525).

20401340155 is a wasteful number, since it uses less digits than its factorization.

20401340155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30678738.

The product of its (nonzero) digits is 2400, while the sum is 25.

Adding to 20401340155 its reverse (55104310402), we get a palindrome (75505650557).

The spelling of 20401340155 in words is "twenty billion, four hundred one million, three hundred forty thousand, one hundred fifty-five".